Developing single-crystalline Ni-rich cathodes is an effective strategy to improve the safety and cycle life of Li-ion batteries(LIBs).However,the easy-to-loss of Li and O in high-temperature lithiation results in uns...Developing single-crystalline Ni-rich cathodes is an effective strategy to improve the safety and cycle life of Li-ion batteries(LIBs).However,the easy-to-loss of Li and O in high-temperature lithiation results in unsatisfactory ordered layered structure and stoichiometry.Herein,we demonstrate the synthesis of highly-ordered and fully-stoichiometric single-crystalline LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(SC-NCM83)cathodes by the regulation of pre-lithiation kinetics.The well-balanced pre-lithiation kinetics have been proved to greatly improve the proportion of layered phase in the intermediate by inhibiting the formation of metastable spinel phase,which promoted the rapid transformation of the intermediate into highly-ordered layered SC-NCM83 in the subsequent lithiation process.After coating a layer of Li_(2)O–B_(2)O_(3),the resultant cathodes deliver superior cycling stability with 90.9%capacity retention at 1C after 300 cycles in pouch-type full batteries.The enhancement mechanism has also been clarified.These findings exhibit fundamental insights into the pre-lithiation kinetics process for guiding the synthesis of high-quality singlecrystalline Ni-rich cathodes.展开更多
Hierarchical ZnO@metal-organic framework @polyaniline(ZnO@MOF@PANI) core-shell nanorod arrays on carbon cloth has been fabricated by combining electrodeposition and hydrothermal method. Well-ordered Zn O nanorods not ...Hierarchical ZnO@metal-organic framework @polyaniline(ZnO@MOF@PANI) core-shell nanorod arrays on carbon cloth has been fabricated by combining electrodeposition and hydrothermal method. Well-ordered Zn O nanorods not only act as a scaffold for growth of MOF/PANI shell but also as Zn source for the formation of MOF. The morphology of ZnO@MOF@PANI composite is greatly influenced by the number of PANI electrodeposition cycles. Their structural and electrochemical properties were characterized with different techniques. The results indicate that the Zn O@MOF@PANI with 13 CV cycles of PANI deposition demonstrates the maximum specific capacitance of 340.7 F g-1 at 1.0 A g-1, good rate capability with84.3% capacitance retention from 1.0 to 10 A g-1 and excellent cycling life of 82.5% capacitance retention after 5000 cycles at high current density of 2.0 A g-1. This optimized core-shell nanoarchitecture endows the composite electrode with short ion diffusion pathway, rapid ion/electron transfer and high utilization of active materials, which thus result in excellent electrochemical performance of the ternary composite.展开更多
As promising energy storage systems,lithium-sulfur(Li-S)batteries have attracted significant attention because of their ultra-high energy densities.However,Li-S battery suffers problems related to the complex phase co...As promising energy storage systems,lithium-sulfur(Li-S)batteries have attracted significant attention because of their ultra-high energy densities.However,Li-S battery suffers problems related to the complex phase conversion that occurs during the charge-discharge process,particularly the deposition of solid Li2S from the liquid-phase polysulfides,which greatly limits its practical application.In this paper,edge-rich MoS2/C hollow microspheres(Edg-MoS2/C HMs)were designed and used to functionalize separator for Li-S battery,resulting in the uniform deposition of Li2S.The microspheres were fabricated through the facile hydrothermal treatment of MoO3-aniline nanowires and a subsequent carbonization process.The obtained Edg-MoS2/C HMs have a strong chemical absorption capability and high density of Li2S binding sites,and exhibit excellent electrocatalytic performance and can effectively hinder the polysulfide shuttle effect and guide the uniform nucleation and growth of Li2S.Furthermore,we demonstrate that the Edg-MoS2/C HMs can effectively regulate the deposition of Li2S and significantly improve the reversibility of the phase conversion of the active sulfur species,especially at high sulfur loadings and high C-rates.As a result,a cell containing a separator functionalized with Edg-MoS2/C HMs exhibited an initial discharge capacity of 935 mAh g-1 at 1.0 C and maintained a capacity of 494 mAh g-1 after 1000 cycles with a sulfur loading of 1.7 mg cm-2.Impressively,at a high sulfur loading of 6.1 mg cm-2 and high rate of 0.5 C,the cell still delivered a high reversible discharge capacity of 478 mAh g-1 after 300 cycles.This work provides fresh insights into energy storage systems related to complex phase conversions.展开更多
Surface engineering is an effective strategy to restrain the generation of rocksalt NiO phase on surface of layered LiNi0.815Co0.15Al0.035O2（NCA） primary nanoparticles, a representative Ni-rich layered oxides cathod...Surface engineering is an effective strategy to restrain the generation of rocksalt NiO phase on surface of layered LiNi0.815Co0.15Al0.035O2（NCA） primary nanoparticles, a representative Ni-rich layered oxides cathode materials. Herein, we demonstrate the kilogram-scale synthesis of few-layer reduced graphene oxide（rGO） conformably coated NCA primary nanoparticles cathode materials by a mechanical wet ball-milling strategy. The lightening rGO coating layer effectively avoids the direct contact of electrolyte and NCA with rapid electrons transfer. As a result, the as-obtained NCA@rGO hybrids with only 1.0 wt% rGO content can deliver a high specific capacity（196 mAh g-1 at 0.2 C） and fast charge/discharge capability（127 mAh g-1 at 5 C）, which is much higher than the corresponding NCA nanoparticles（95 mAh g-1 at 5 C）. Even after100 cycles at 1 C, 91.7% of initial reversible capacity is still maintained. Furthermore, a prismatic pouch cell（240 mAh） is also successfully assembled with the commercial graphite anode.展开更多
Developing an efficient synthesis protocol to simultaneously control 2D nanomaterials’size and dispersion is the pivot to optimize their electrochemical performance.Herein,we report the synthesis of uniform MoS_(2) n...Developing an efficient synthesis protocol to simultaneously control 2D nanomaterials’size and dispersion is the pivot to optimize their electrochemical performance.Herein,we report the synthesis of uniform MoS_(2) nanocrystals well-anchored into the void space of porous carbon(donated as MoS_(2)3C hybrids)by a simple confined reaction in metal–organic framework(MOF)during carbonization process.The strong confinement effect refrain MoS2 growth and aggregation,generating abundant active centers and edges,which contribute fast lithium/potassium reaction kinetics.In addition to the hybridization with the derived carbon,the MoS_(2)3C hybrids exhibit rapid Liþtransfer rate(~109 cm^(2) s 1)and greatly improved electronic conductivity.Consequently,the MoS23C hybrids show ultrafast rate performances and satisfactory cycling stabilities as anode materials for both lithium and potassium ion batteries.This work demonstrates a universal tactic to achieve high dispersive 2D nanomaterials with tailorable particle size.展开更多
Photocurrent-voltage characterization is a crucial method for assessing key parameters in x-ray or y-ray semiconductor detectors,especially the carrier mobility lifetime product.However,the high biases during photocur...Photocurrent-voltage characterization is a crucial method for assessing key parameters in x-ray or y-ray semiconductor detectors,especially the carrier mobility lifetime product.However,the high biases during photocurrent measurements tend to cause severe ion migration,which can lead to the instability and inaccuracy of the test results.Given the mixed electronic-ionic charac teristics,it is imperative to devise novel methods capable of precisely measuring photocurrentvoltage characteristics under high bias conditions,free from interference caused by ion migration.In this paper,pulsed bias is employed to explore the photocurrent-voltage characteristics of MAPbBr_(3) single crystals.The method yields stable photocurrent-voltage characteristics at a pulsed bias of up to 30 V,proving to be effective in mitigating ion migration.Through fitting the modified Hecht equation,we determined the mobility lifetime products of 1.0×10^(2) cm^(2)·V^(-1)for hole and 2.78×10~(-3)cm^(2)·V^(-1)for electron.This approach offers a promising solution for accurately measuring the transport properties of carriers in perovskite.展开更多
Defect-engineered carbon materials have been emerged as promising electrocatalysts for oxygen reduction reaction(ORR)in metal-air batteries.Developing a facile strategy for the preparation of highly active nanocarbon ...Defect-engineered carbon materials have been emerged as promising electrocatalysts for oxygen reduction reaction(ORR)in metal-air batteries.Developing a facile strategy for the preparation of highly active nanocarbon electrocatalysts remains challenging.Herein,a low-cost and simple route is developed to synthesize defective graphene by pyrolyzing the mixture of glucose and carbon nitride.Molecular dynamics simulations reveal that the graphene formation is ascribed to two-dimensional layered feature of carbon nitride,and high compatibility of carbon nitride/glucose systems.Structural measurements suggest that the graphene possesses rich edge and topological defects.The graphene catalyst exhibits higher power density than commercial Pt/C catalyst in a primary Zn-air battery.Combining experimental results and theoretical thermodynamic analysis,it is identified that graphitic nitrogen-modified topological defects at carbon framework edges are responsible for the decent ORR performance.The strategy presented in this work can be can be scaled up readily to fabricate defective carbon materials.展开更多
Bismuth-based materials(e.g., metallic, oxides and subcarbonate) are emerged as promising electrocatalysts for converting CO_(2) to formate. However, Bio-based electrocatalysts possess high overpotentials, while bismu...Bismuth-based materials(e.g., metallic, oxides and subcarbonate) are emerged as promising electrocatalysts for converting CO_(2) to formate. However, Bio-based electrocatalysts possess high overpotentials, while bismuth oxides and subcarbonate encounter stability issues. This work is designated to exemplify that the operando synthesis can be an effective means to enhance the stability of electrocatalysts under operando CO_(2)RR conditions. A synthetic approach is developed to electrochemically convert Bi^(O)Cl into Cl-containing subcarbonate(Bi_(2)O_(2)(CO_(3))_(x)Cl_(y)) under operando CO_(2)RR conditions. The systematic operando spectroscopic studies depict that BiOCl is converted to Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) via a cathodic potential-promoted anion-exchange process. The operando synthesizedBi_(2)O_(2)(CO_(3))_(x)Cl_(y) can tolerate-1.0 V versus RHE, while for the wet-chemistry synthesized pure Bi_(2)O_(2)CO_(3),the formation of metallic Bio occurs at-0.6 V versus RHE. At-0.8 V versus RHE, Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) can readily attain a FEHCOO-of 97.9%,much higher than that of the pure Bi_(2)O_(2)CO_(3)(81.3%). DFT calculations indicate that differing from the pure Bi_(2)O_(2)CO_(3)-catalyzed CO_(2)RR, where formate is formed via a *OCHO intermediate step that requires a high energy input energy of 2.69 eV to proceed, the formation of H COO-over Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) has proceeded via a *COOH intermediate step that only requires low energy input of 2.56 eV.展开更多
Passivation,as a classical surface treatment technique,has been widely accepted in start-of-the-art perovskite solar cells(PSCs)that can effectively modulate the electronic and chemical property of defective perovskit...Passivation,as a classical surface treatment technique,has been widely accepted in start-of-the-art perovskite solar cells(PSCs)that can effectively modulate the electronic and chemical property of defective perovskite surface.The discovery of inorganic passivation compounds,such as oxysalts,has largely advanced the efficiency and lifetime of PSCs on account of its favorable electrical property and remarkable inherent stability,but a lack of deep understanding of how its local configuration affects the passivation effectiveness is a huge impediment for future interfacial molecular engineering.Here,we demonstrate the central-atom-dependent-passivation of oxysalt on perovskite surface,in which the central atoms of oxyacid anions dominate the interfacial oxygen-bridge strength.We revealed that the balance of local interactions between the central atoms of oxyacid anions(e.g.,N,C,S,P,Si)and the metal cations on perovskite surface(e.g.,Pb)generally determines the bond formation at oxysalt/perovskite interface,which can be understood by the bond order conservation principle.Silicate with less electronegative Si central atoms provides strong O-Pb motif and improved passivation effect,delivering a champion efficiency of 17.26%for CsPbI2Br solar cells.Our strategy is also universally effective in improving the device performance of several commonly used perovskite compositions.展开更多
In recent years, perovskite solar cells(PSCs) have propelled into the limelight owing to rapid development of efficiency;however, the abundant defects at the perovskite grain boundaries result in unwanted energy loss ...In recent years, perovskite solar cells(PSCs) have propelled into the limelight owing to rapid development of efficiency;however, the abundant defects at the perovskite grain boundaries result in unwanted energy loss and structural degradation. Here, the grain boundaries of perovskite polycrystalline films have been found to act as nanocapillaries for capturing perovskite quantum dots(PQDs), which enable the conformal assemble of PQDs at the top interspace between perovskite grains. The existence of PQDs passivated the surface defects, optimized the interfacial band alignments, and ultimately improved the power conversion efficiency from 19.27% to 22.47% in inverted PSCs. Our findings open up the possibility of selective assembly and structural modulation of the perovskite nanostructures towards efficient and stable PSCs.展开更多
Organometal halide perovskites have recently emerged with a huge potential for photovoltaic applications. Moreover, preparation of high-quality perovskite crystals with controlled morphology is of great significance f...Organometal halide perovskites have recently emerged with a huge potential for photovoltaic applications. Moreover, preparation of high-quality perovskite crystals with controlled morphology is of great significance for the fundamental studies such as optical and electrical properties, as well as the applications. Here, we report a one-pot solvothermal process to synthesize sheet-shaped CH3NH3PbBr3 single crystals with the lateral size of 100 μm and the thickness of 3–8 μm. Furthermore, a controlled etching behavior on the crystalline surface was demonstrated, which could be the irregular collapse of the crystalline surface caused by the local accumulation of methylammonium cations. Using this technique,CH3NH3PbBr3 single crystal sheets could be used in the various optoelectronic devices, such as nanolaser,optical sensors, photodetectors and field effect transistors.展开更多
Electrochemical oxygen evolution reaction (OER) is a main efficiency bottleneck of water electrolysis.Commercial ruthenium oxide (RuO_(2)) catalyst displays remarkable activities but poor stability for OER.The instabi...Electrochemical oxygen evolution reaction (OER) is a main efficiency bottleneck of water electrolysis.Commercial ruthenium oxide (RuO_(2)) catalyst displays remarkable activities but poor stability for OER.The instability stems from lattice oxygen oxidation,resulting in the oxidation of Ru^(4+) to soluble Ru^(4+)(x>4) species.Herein,we redirect dynamic structural evolution of Ru-based catalysts through introducing oxidized nickel (Ni) components.By virtue of comprehensive structural characterizations,such as high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM),X-ray photoelectron spectroscopy (XPS),operando Raman and so forth,it is demonstrated that when the atomic content of Ni exceeds that of ruthenium (Ru),the Ni components can efficiently inhibit the Ru^(4+) oxidation and structural collapse.Density functional theory (DFT) calculations suggest that the introduction of Ni component hinders the formation of oxygen vacancies,and makes lattice oxygen mediated mechanism turn to adsorbate evolution mechanism,which eventually improves the stability.The optimized nickel-contained RuO_(2) catalyst delivers an effective reactivity with an overpotential of less than 215 m V to attain 10 m A cm^(-2) and remarkable stability with only 5 mV increment after 5000 potential cycles.This work provides insights into the origin of dynamic structural evolution of transition-metalmodified RuO_(2) electrocatalysts.展开更多
Eu2＋-doped oxyapatite SrxLalo-x （SiO4）6O3-x/2 phosphors are prepared by sofid-state reaction at high temper- atures under reducing atmosphere. Their crystal structures and photoluminescenee are investigated by x-ra...Eu2＋-doped oxyapatite SrxLalo-x （SiO4）6O3-x/2 phosphors are prepared by sofid-state reaction at high temper- atures under reducing atmosphere. Their crystal structures and photoluminescenee are investigated by x-ray diffraction （XRD） and fluorescence spectroscopy, respectively. The XlZtD results indicate that the samples are pure oxyapatite phase （P63/m space group）. The fluorescence spectra show two peaks corresponding to two sites （4f and 6h sites） for Eu2＋ in the host lattice. As the Eu2＋ content influences the intensity ratio of the two observed emission peaks, the photoluminescence mechanism is discussed.展开更多
Highly active and durable bifunctional electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) play a pivotal role in overall water splitting. Herein, we demonstrate the construction...Highly active and durable bifunctional electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) play a pivotal role in overall water splitting. Herein, we demonstrate the construction of interface-strengthened CoP nanosheet array with Co2P nanoparticles as such an electrocatalyst through a facile hydrothermal reaction and the subsequent phosphorization process. The twodimensional (2D) nanosheets with thickness of^55 nm expose a great number of active sites. The surface chemical state indicates that the strongly coupled CoP/Co2P electrocatalysts can adsorb or generate more targeted intermediates (e.g. OH- or OOH*) for both HER/OER. As a result, the CoP/Co2P electrocatalysts exhibit small overpotentials of 68 and 256 mV to drive 10 mA cm^-2 for HER and OER, respectively, outperforming most of the recently reported Co-based electrocatalysts. Furthermore, an alkaline electrolyzer assembled by using CoP/Co2P as both cathode and anode can achieve a current density of 10 mA cm^-2 at a low voltage of 1.57 V and work continuously for over 58 h. This work provides a feasible structural design for transition metal phosphides electrocatalysts with efficient and stable overall water splitting.展开更多
Tailoring valence electron delocalization of transition metal center is of importance to achieve highly-active electrocatalysts for oxygen evolution reaction(OER).Herein,we demonstrate a“poor sulfur”route to synthes...Tailoring valence electron delocalization of transition metal center is of importance to achieve highly-active electrocatalysts for oxygen evolution reaction(OER).Herein,we demonstrate a“poor sulfur”route to synthesize surface electron-deficient Co_(9)S_(8) nanoarrays,where the binding energy(BE)of Co metal center is considerably higher than all reported Co_(9)S_(8)-based electrocatalysts.The resulting Co_(9)S_(8) electrocatalysts only require the overpotentials(h)of 265 and 326 mV at 10 and 100 mA cm^(-2) with a low Tafel slope of 56 mV dec^-(1) and a 60 hlasting stability in alkaline media.The OER kinetics are greatly expedited with a low reaction activation energy of 27.9 kJ mol^-(1) as well as abundant OOH*key intermediates(24%),thus exhibiting excellent catalytic performances.The surface electron-deficient engineering gives an available strategy to improve the catalytic activity of other advanced non-noble electrocatalysts.展开更多
The low sulfur utilization and fast capacity fading resulting from the sluggish redox reaction and abominable polysulfides shuttle greatly hinder the practical applications of lithium-sulfur(Li-S) batteries.Herein, we...The low sulfur utilization and fast capacity fading resulting from the sluggish redox reaction and abominable polysulfides shuttle greatly hinder the practical applications of lithium-sulfur(Li-S) batteries.Herein, we develop a facile "in-situ growth" method to decorate ultra-small Mo2 C nanoparticles(USMo2 C) on the surface of Ketjen Black(KB) to functionalize the commercial polypropylene(PP) separators,which can accelerate the redox kinetics of lithium polysulfides conversion and effectively increase the utilization of sulfur for Li-S batteries. Importantly, the US-Mo2 C nanoparticles have abundant sites for chemical adsorption towards polysulfides and the conductive carbon networks of KB have cross-linked pore channels, which can promote electron transport and provide physical barrier and volume expansion space for polysulfides. Due to the combined effects of the US-Mo2 C and KB, Li-S cells employing the multifunctional PP separators modified with KB/US-Mo2 C composite(KB/US-Mo2 C@PP) exhibit a high specific capacity(1212.8 mAh g^(-1) at 0.2 C), and maintain a reversible capacity of 1053.3 m Ah g^(-1) after 100 cycles.More importantly, the KB/US-Mo2 C@PP cells with higher sulfur mass loading of 4.9 mg cm^(-2) have superb areal capacity of 2.3 mAh cm^(-2). This work offers a novel and promising perspective for high-performance Li-S batteries from both the shuttle effect and the complex polysulfides conversion.展开更多
Oxygen vacancies (V_(o)) engineering has been deemed to an effective tactic for enhancing Li-ion storage kinetics and reversibility of SnO_(2)-based anode materials.Herein,we demonstrated the confinement of ultrahigh ...Oxygen vacancies (V_(o)) engineering has been deemed to an effective tactic for enhancing Li-ion storage kinetics and reversibility of SnO_(2)-based anode materials.Herein,we demonstrated the confinement of ultrahigh V_(o)SnO_(2) nanocrystals into N-doped carbon frameworks to boost their high-rate and cycle life.Density functional theory (DFT) calculations reveal that abundant V_(o) in SnO_(2) facilitates the adsorption to Li-ion with remarkably increased carrier concentration.The 6.0 nm-sized SnO_(2) particles and the embedded design effectively stabilize the structural integrity during de-/lithiation.Meantime,the as-formed large hetero-interface also expedites the electron transfer.These merits guarantee its high-rate performance and superior cycling stability.Consequently,this sample exhibits a high capacity of 1368.9m Ah g^(-1)at 0.1 A g^(-1),and can still maintain 488.5 mAh g^(-1)at 10 A g^(-1)and a long life over 400 cycles at 5 A g^(-1)with 96.6%capacity retention,which is among the best report for Sn-contained anode materials.This work sheds light on ultrahigh Vo and structural design in conversion-type oxides for highperformance lithium-ion batteries (LIBs).展开更多
Surface modification by metal ion has been considered a promising strategy to enhance the photocatalytic activity by extending optical response and improving charge separation and transportation.Here,univalent copper ...Surface modification by metal ion has been considered a promising strategy to enhance the photocatalytic activity by extending optical response and improving charge separation and transportation.Here,univalent copper species were modified on ZnIn_(2)S_(4)photocatalyst via an in-situ photodeposition method,exhibiting a much higher H2evolution rate of 41.10±3.43 mmol g^(-1)h^(-1)and an impressive apparent quantum efficiency(AQE)of 20.81%at 420±15 nm.Our characterizations indicate that the surface modification by copper species can broaden light utilization as well as promote charge separation and transportation.Besides,the density functional theory(DFT)results further exhibit that the energy levels(LUMO and HOMO)for copper-surface modified ZnIn_(2)S_(4)present spatial separation,locating on the Zn-S and In-S layers,respectively,which can suppress the recombination of electron and hole and thus achieves higher photocatalytic H2evolution efficiency.展开更多
Flexible aqueous Ni//Zn batteries have attracted much attention as promising candidates for energy storage in the field of flexible electronics.However,the Ni-based cathodes still face the challenges of poor conductiv...Flexible aqueous Ni//Zn batteries have attracted much attention as promising candidates for energy storage in the field of flexible electronics.However,the Ni-based cathodes still face the challenges of poor conductivity,confined charge/mass transfer,and non-flexibility.In this work,we designed a hollow tubular structure consisting of a conductive silver nanowire (Ag NW) wrapped by active Ni Co layered double hydroxide (LDH),for enhancing the electrical conductivity,improving the charge/mass transfer kinetics,and facilitating the ion penetration.By optimizing the contents of Ni,Co and Ag NW,the Ni_(4)Co LDH@Ag_(1.5)NW composite shows a maximum specific capacity of 115.83 m Ah g^(-1)at 0.1 A g^(-1)measured in a two-electrode system.Highlightingly,the flexible aqueous Ni//Zn battery assembled by Ni_(4)Co LDH@Ag_(1.5)NW interwoven with multi-walled carbon nanotube cathode and Zn foil anode realizes a high power density of 160μW cm^(-2)at the energy density of 23.14μWh cm^(-2),which is superior compared with those of oxide/hydroxide based devices and even higher than those of many carbon-based supercapacitors,showing its promising potentials for flexible energy storage applications.展开更多
Searching for efficient and robust non-noble electrocatalysts for hydrogen generation is extremely desirable for future green energy systems.Here, we present the synthesis of integrated Ni-P-S nanosheets array includi...Searching for efficient and robust non-noble electrocatalysts for hydrogen generation is extremely desirable for future green energy systems.Here, we present the synthesis of integrated Ni-P-S nanosheets array including Ni_2P and NiS on nickel foam by a simple simultaneous phosphorization and sulfurization strategy. The resultant sample with optimal composition exhibits superior electrocatalytic performance for hydrogen evolution reaction(HER) in a wide pH range. In alkaline media, it can generate current densities of 10, 20 and 100 mA cm^(-2) at low overpotentials of only-101.9,-142.0 and-207.8 mV with robust durability. It still exhibits high electrocatalytic activities even in acid or neutral media. Such superior electrocatalytic performances can be mainly attributed to the synergistic enhancement of the hybrid Ni-P-S nanosheets array with integration microstructure. The kind of catalyst gives a new insight on achieving efficient and robust hydrogen generation.展开更多
基金supported by the National Natural Science Foundation of China(21975074,91834301)the Innovation Program of Shanghai Municipal Education Commissionthe Fundamental Research Funds for the Central Universities.
文摘Developing single-crystalline Ni-rich cathodes is an effective strategy to improve the safety and cycle life of Li-ion batteries(LIBs).However,the easy-to-loss of Li and O in high-temperature lithiation results in unsatisfactory ordered layered structure and stoichiometry.Herein,we demonstrate the synthesis of highly-ordered and fully-stoichiometric single-crystalline LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(SC-NCM83)cathodes by the regulation of pre-lithiation kinetics.The well-balanced pre-lithiation kinetics have been proved to greatly improve the proportion of layered phase in the intermediate by inhibiting the formation of metastable spinel phase,which promoted the rapid transformation of the intermediate into highly-ordered layered SC-NCM83 in the subsequent lithiation process.After coating a layer of Li_(2)O–B_(2)O_(3),the resultant cathodes deliver superior cycling stability with 90.9%capacity retention at 1C after 300 cycles in pouch-type full batteries.The enhancement mechanism has also been clarified.These findings exhibit fundamental insights into the pre-lithiation kinetics process for guiding the synthesis of high-quality singlecrystalline Ni-rich cathodes.
基金supported by the National Key R&D Program of China(2016YFE0131200)the National Natural Science Foundation of China(51702098)+1 种基金International Cooperation Project of Shanghai Municipal Science and Technology Committee(15520721100,18520744400)Research Program supported by the Ministry of Education,Youth,and Sports of the Czech Republic(LTACH17015)
文摘Hierarchical ZnO@metal-organic framework @polyaniline(ZnO@MOF@PANI) core-shell nanorod arrays on carbon cloth has been fabricated by combining electrodeposition and hydrothermal method. Well-ordered Zn O nanorods not only act as a scaffold for growth of MOF/PANI shell but also as Zn source for the formation of MOF. The morphology of ZnO@MOF@PANI composite is greatly influenced by the number of PANI electrodeposition cycles. Their structural and electrochemical properties were characterized with different techniques. The results indicate that the Zn O@MOF@PANI with 13 CV cycles of PANI deposition demonstrates the maximum specific capacitance of 340.7 F g-1 at 1.0 A g-1, good rate capability with84.3% capacitance retention from 1.0 to 10 A g-1 and excellent cycling life of 82.5% capacitance retention after 5000 cycles at high current density of 2.0 A g-1. This optimized core-shell nanoarchitecture endows the composite electrode with short ion diffusion pathway, rapid ion/electron transfer and high utilization of active materials, which thus result in excellent electrochemical performance of the ternary composite.
基金financially supported by National Natural Science Foundation of China (No. 51672083)Program of Shanghai Academic/Technology Research Leader (18XD1401400)+3 种基金Basic Research Program of Shanghai (17JC1404702)Leading talents in Shanghai in 2018The 111 project (B14018)the Fundamental Research Funds for the Central Universities (222201718002)
文摘As promising energy storage systems,lithium-sulfur(Li-S)batteries have attracted significant attention because of their ultra-high energy densities.However,Li-S battery suffers problems related to the complex phase conversion that occurs during the charge-discharge process,particularly the deposition of solid Li2S from the liquid-phase polysulfides,which greatly limits its practical application.In this paper,edge-rich MoS2/C hollow microspheres(Edg-MoS2/C HMs)were designed and used to functionalize separator for Li-S battery,resulting in the uniform deposition of Li2S.The microspheres were fabricated through the facile hydrothermal treatment of MoO3-aniline nanowires and a subsequent carbonization process.The obtained Edg-MoS2/C HMs have a strong chemical absorption capability and high density of Li2S binding sites,and exhibit excellent electrocatalytic performance and can effectively hinder the polysulfide shuttle effect and guide the uniform nucleation and growth of Li2S.Furthermore,we demonstrate that the Edg-MoS2/C HMs can effectively regulate the deposition of Li2S and significantly improve the reversibility of the phase conversion of the active sulfur species,especially at high sulfur loadings and high C-rates.As a result,a cell containing a separator functionalized with Edg-MoS2/C HMs exhibited an initial discharge capacity of 935 mAh g-1 at 1.0 C and maintained a capacity of 494 mAh g-1 after 1000 cycles with a sulfur loading of 1.7 mg cm-2.Impressively,at a high sulfur loading of 6.1 mg cm-2 and high rate of 0.5 C,the cell still delivered a high reversible discharge capacity of 478 mAh g-1 after 300 cycles.This work provides fresh insights into energy storage systems related to complex phase conversions.
基金supported by the National Natural Science Foundation of China (21522602, 51672082, 91534202, and 91534122)Shanghai Rising-Star Program (15QA1401200)+1 种基金the Program for Shanghai Youth Top-notch Talentthe Fundamental Research Funds for the Central Universities (222201718002)
文摘Surface engineering is an effective strategy to restrain the generation of rocksalt NiO phase on surface of layered LiNi0.815Co0.15Al0.035O2（NCA） primary nanoparticles, a representative Ni-rich layered oxides cathode materials. Herein, we demonstrate the kilogram-scale synthesis of few-layer reduced graphene oxide（rGO） conformably coated NCA primary nanoparticles cathode materials by a mechanical wet ball-milling strategy. The lightening rGO coating layer effectively avoids the direct contact of electrolyte and NCA with rapid electrons transfer. As a result, the as-obtained NCA@rGO hybrids with only 1.0 wt% rGO content can deliver a high specific capacity（196 mAh g-1 at 0.2 C） and fast charge/discharge capability（127 mAh g-1 at 5 C）, which is much higher than the corresponding NCA nanoparticles（95 mAh g-1 at 5 C）. Even after100 cycles at 1 C, 91.7% of initial reversible capacity is still maintained. Furthermore, a prismatic pouch cell（240 mAh） is also successfully assembled with the commercial graphite anode.
基金the National Natural Science Foundation of China(21975074,91534202 and 91834301)the Basic Research Program of Shanghai(17JC1402300)+2 种基金the Shanghai Scientific and Technological Innovation Project(18JC1410500)the National Program for Support of TopNotch Young Professionalsthe Fundamental Research Funds for the Central Universities(222201718002).
文摘Developing an efficient synthesis protocol to simultaneously control 2D nanomaterials’size and dispersion is the pivot to optimize their electrochemical performance.Herein,we report the synthesis of uniform MoS_(2) nanocrystals well-anchored into the void space of porous carbon(donated as MoS_(2)3C hybrids)by a simple confined reaction in metal–organic framework(MOF)during carbonization process.The strong confinement effect refrain MoS2 growth and aggregation,generating abundant active centers and edges,which contribute fast lithium/potassium reaction kinetics.In addition to the hybridization with the derived carbon,the MoS_(2)3C hybrids exhibit rapid Liþtransfer rate(~109 cm^(2) s 1)and greatly improved electronic conductivity.Consequently,the MoS23C hybrids show ultrafast rate performances and satisfactory cycling stabilities as anode materials for both lithium and potassium ion batteries.This work demonstrates a universal tactic to achieve high dispersive 2D nanomaterials with tailorable particle size.
基金Project supported by the National Natural Science Foundation of China (Grant No.62104234)Shanghai Explorer Program (Grant No.22TS1400100)。
文摘Photocurrent-voltage characterization is a crucial method for assessing key parameters in x-ray or y-ray semiconductor detectors,especially the carrier mobility lifetime product.However,the high biases during photocurrent measurements tend to cause severe ion migration,which can lead to the instability and inaccuracy of the test results.Given the mixed electronic-ionic charac teristics,it is imperative to devise novel methods capable of precisely measuring photocurrentvoltage characteristics under high bias conditions,free from interference caused by ion migration.In this paper,pulsed bias is employed to explore the photocurrent-voltage characteristics of MAPbBr_(3) single crystals.The method yields stable photocurrent-voltage characteristics at a pulsed bias of up to 30 V,proving to be effective in mitigating ion migration.Through fitting the modified Hecht equation,we determined the mobility lifetime products of 1.0×10^(2) cm^(2)·V^(-1)for hole and 2.78×10~(-3)cm^(2)·V^(-1)for electron.This approach offers a promising solution for accurately measuring the transport properties of carriers in perovskite.
基金supported by the National Natural Science Foundation of China(21838003,91834301 and 21978278)the Shanghai Scientific and Technological Innovation Project(18JC1410500 and 19JC1410400)the Fundamental Research Funds for the Central Universities(222201718002).
文摘Defect-engineered carbon materials have been emerged as promising electrocatalysts for oxygen reduction reaction(ORR)in metal-air batteries.Developing a facile strategy for the preparation of highly active nanocarbon electrocatalysts remains challenging.Herein,a low-cost and simple route is developed to synthesize defective graphene by pyrolyzing the mixture of glucose and carbon nitride.Molecular dynamics simulations reveal that the graphene formation is ascribed to two-dimensional layered feature of carbon nitride,and high compatibility of carbon nitride/glucose systems.Structural measurements suggest that the graphene possesses rich edge and topological defects.The graphene catalyst exhibits higher power density than commercial Pt/C catalyst in a primary Zn-air battery.Combining experimental results and theoretical thermodynamic analysis,it is identified that graphitic nitrogen-modified topological defects at carbon framework edges are responsible for the decent ORR performance.The strategy presented in this work can be can be scaled up readily to fabricate defective carbon materials.
基金financially supported by Australian Research Council Discovery Project(DP200100965)。
文摘Bismuth-based materials(e.g., metallic, oxides and subcarbonate) are emerged as promising electrocatalysts for converting CO_(2) to formate. However, Bio-based electrocatalysts possess high overpotentials, while bismuth oxides and subcarbonate encounter stability issues. This work is designated to exemplify that the operando synthesis can be an effective means to enhance the stability of electrocatalysts under operando CO_(2)RR conditions. A synthetic approach is developed to electrochemically convert Bi^(O)Cl into Cl-containing subcarbonate(Bi_(2)O_(2)(CO_(3))_(x)Cl_(y)) under operando CO_(2)RR conditions. The systematic operando spectroscopic studies depict that BiOCl is converted to Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) via a cathodic potential-promoted anion-exchange process. The operando synthesizedBi_(2)O_(2)(CO_(3))_(x)Cl_(y) can tolerate-1.0 V versus RHE, while for the wet-chemistry synthesized pure Bi_(2)O_(2)CO_(3),the formation of metallic Bio occurs at-0.6 V versus RHE. At-0.8 V versus RHE, Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) can readily attain a FEHCOO-of 97.9%,much higher than that of the pure Bi_(2)O_(2)CO_(3)(81.3%). DFT calculations indicate that differing from the pure Bi_(2)O_(2)CO_(3)-catalyzed CO_(2)RR, where formate is formed via a *OCHO intermediate step that requires a high energy input energy of 2.69 eV to proceed, the formation of H COO-over Bi_(2)O_(2)(CO_(3))_(x)Cl_(y) has proceeded via a *COOH intermediate step that only requires low energy input of 2.56 eV.
基金Ze Qing Lin and Hui Jun Lian contributed equally to this work.This work was financially supported by National Natural Science Fund for Excellent Young Scholars(52022030)International(Regional)Cooperation and Exchange Projects of the National Natural Science Foundation of China(51920105003)+4 种基金National Natural Science Fund for Distinguished Young Scholars(51725201)National Ten Thousand Talent Program for Young Top-notch Talent,National Natural Science Foundation of China(51902185,51972111)Innovation Program of Shanghai Municipal Education Commission(E00014)Shanghai Engineering Research Center of Hierarchical Nanomaterials(18DZ2252400)The authors also thank the Frontiers Science Center for Materiobiology and Dynamic Chemistry.
文摘Passivation,as a classical surface treatment technique,has been widely accepted in start-of-the-art perovskite solar cells(PSCs)that can effectively modulate the electronic and chemical property of defective perovskite surface.The discovery of inorganic passivation compounds,such as oxysalts,has largely advanced the efficiency and lifetime of PSCs on account of its favorable electrical property and remarkable inherent stability,but a lack of deep understanding of how its local configuration affects the passivation effectiveness is a huge impediment for future interfacial molecular engineering.Here,we demonstrate the central-atom-dependent-passivation of oxysalt on perovskite surface,in which the central atoms of oxyacid anions dominate the interfacial oxygen-bridge strength.We revealed that the balance of local interactions between the central atoms of oxyacid anions(e.g.,N,C,S,P,Si)and the metal cations on perovskite surface(e.g.,Pb)generally determines the bond formation at oxysalt/perovskite interface,which can be understood by the bond order conservation principle.Silicate with less electronegative Si central atoms provides strong O-Pb motif and improved passivation effect,delivering a champion efficiency of 17.26%for CsPbI2Br solar cells.Our strategy is also universally effective in improving the device performance of several commonly used perovskite compositions.
基金financially supported by the National Ten Thousand Talent Program for Young Top-notch Talentthe National Natural Science Fund for Excellent Young Scholars (52022030)+8 种基金the National Natural Science Foundation of China (51972111,52203330)the Shanghai Pilot Program for Basic Research(22TQ1400100-5)the “Dawn” Program of Shanghai Education Commission (22SG28)the Shanghai Municipal Natural Science Foundation (22ZR1418000)the Science and Technology Innovation Plan of Shanghai Science and Technology Commission(22YF1410000)the Postdoctoral Research Foundation of China(2021M701190)the Fundamental Research Funds for the Central Universities (JKM01221621, JKM01221678)the Major Science and Technology Projects of Inner Mongolia Autonomous Region(2021ZD0042)Shanghai Engineering Research Center of Hierarchical Nanomaterials (18DZ2252400)。
文摘In recent years, perovskite solar cells(PSCs) have propelled into the limelight owing to rapid development of efficiency;however, the abundant defects at the perovskite grain boundaries result in unwanted energy loss and structural degradation. Here, the grain boundaries of perovskite polycrystalline films have been found to act as nanocapillaries for capturing perovskite quantum dots(PQDs), which enable the conformal assemble of PQDs at the top interspace between perovskite grains. The existence of PQDs passivated the surface defects, optimized the interfacial band alignments, and ultimately improved the power conversion efficiency from 19.27% to 22.47% in inverted PSCs. Our findings open up the possibility of selective assembly and structural modulation of the perovskite nanostructures towards efficient and stable PSCs.
基金financially supported by the National Natural Science Foundation of China (51602103)the National Natural Science Funds for Distinguished Young Scholar (51725201)+4 种基金Young Elite Scientists Sponsorship Program by CAST (2017QNRC001)Shanghai Pujiang Program (18PJD009)“Chen Guang” Project supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation (15CG26)Fundamental Research Funds for the Central Universities (222201718002)the Major Research plan of National Natural Science Foundation of China (91534202)
文摘Organometal halide perovskites have recently emerged with a huge potential for photovoltaic applications. Moreover, preparation of high-quality perovskite crystals with controlled morphology is of great significance for the fundamental studies such as optical and electrical properties, as well as the applications. Here, we report a one-pot solvothermal process to synthesize sheet-shaped CH3NH3PbBr3 single crystals with the lateral size of 100 μm and the thickness of 3–8 μm. Furthermore, a controlled etching behavior on the crystalline surface was demonstrated, which could be the irregular collapse of the crystalline surface caused by the local accumulation of methylammonium cations. Using this technique,CH3NH3PbBr3 single crystal sheets could be used in the various optoelectronic devices, such as nanolaser,optical sensors, photodetectors and field effect transistors.
基金supported by the National Natural Science Foundation of China (21978278, 21838003 and 91834301)the Shanghai Scientific and Technological Innovation Project (18JC1410500 and 19JC1410400)the Fundamental Research Funds for the Central Universities (222201718002)。
文摘Electrochemical oxygen evolution reaction (OER) is a main efficiency bottleneck of water electrolysis.Commercial ruthenium oxide (RuO_(2)) catalyst displays remarkable activities but poor stability for OER.The instability stems from lattice oxygen oxidation,resulting in the oxidation of Ru^(4+) to soluble Ru^(4+)(x>4) species.Herein,we redirect dynamic structural evolution of Ru-based catalysts through introducing oxidized nickel (Ni) components.By virtue of comprehensive structural characterizations,such as high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM),X-ray photoelectron spectroscopy (XPS),operando Raman and so forth,it is demonstrated that when the atomic content of Ni exceeds that of ruthenium (Ru),the Ni components can efficiently inhibit the Ru^(4+) oxidation and structural collapse.Density functional theory (DFT) calculations suggest that the introduction of Ni component hinders the formation of oxygen vacancies,and makes lattice oxygen mediated mechanism turn to adsorbate evolution mechanism,which eventually improves the stability.The optimized nickel-contained RuO_(2) catalyst delivers an effective reactivity with an overpotential of less than 215 m V to attain 10 m A cm^(-2) and remarkable stability with only 5 mV increment after 5000 potential cycles.This work provides insights into the origin of dynamic structural evolution of transition-metalmodified RuO_(2) electrocatalysts.
文摘Eu2＋-doped oxyapatite SrxLalo-x （SiO4）6O3-x/2 phosphors are prepared by sofid-state reaction at high temper- atures under reducing atmosphere. Their crystal structures and photoluminescenee are investigated by x-ray diffraction （XRD） and fluorescence spectroscopy, respectively. The XlZtD results indicate that the samples are pure oxyapatite phase （P63/m space group）. The fluorescence spectra show two peaks corresponding to two sites （4f and 6h sites） for Eu2＋ in the host lattice. As the Eu2＋ content influences the intensity ratio of the two observed emission peaks, the photoluminescence mechanism is discussed.
基金supported by the National Natural Science Foundation of China (21838003, 91534122)the Social Development Program of Shanghai (17DZ1200900)+2 种基金the Shanghai Scientific and Technological Innovation Project (18JC1410600)the Program for Shanghai Youth Top-notch Talentthe Fundamental Research Funds for the Central Universities (222201718002)
文摘Highly active and durable bifunctional electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) play a pivotal role in overall water splitting. Herein, we demonstrate the construction of interface-strengthened CoP nanosheet array with Co2P nanoparticles as such an electrocatalyst through a facile hydrothermal reaction and the subsequent phosphorization process. The twodimensional (2D) nanosheets with thickness of^55 nm expose a great number of active sites. The surface chemical state indicates that the strongly coupled CoP/Co2P electrocatalysts can adsorb or generate more targeted intermediates (e.g. OH- or OOH*) for both HER/OER. As a result, the CoP/Co2P electrocatalysts exhibit small overpotentials of 68 and 256 mV to drive 10 mA cm^-2 for HER and OER, respectively, outperforming most of the recently reported Co-based electrocatalysts. Furthermore, an alkaline electrolyzer assembled by using CoP/Co2P as both cathode and anode can achieve a current density of 10 mA cm^-2 at a low voltage of 1.57 V and work continuously for over 58 h. This work provides a feasible structural design for transition metal phosphides electrocatalysts with efficient and stable overall water splitting.
基金supported by the National Natural Science Foundation of China(21838003,21808061 and 91534122)the Social Development Program of Shanghai(17DZ1200900)+1 种基金the Shanghai Scientific and Technological Innovation Project(18JC1410600)he Fundamental Research Funds for the Central Universities(222201718002).
文摘Tailoring valence electron delocalization of transition metal center is of importance to achieve highly-active electrocatalysts for oxygen evolution reaction(OER).Herein,we demonstrate a“poor sulfur”route to synthesize surface electron-deficient Co_(9)S_(8) nanoarrays,where the binding energy(BE)of Co metal center is considerably higher than all reported Co_(9)S_(8)-based electrocatalysts.The resulting Co_(9)S_(8) electrocatalysts only require the overpotentials(h)of 265 and 326 mV at 10 and 100 mA cm^(-2) with a low Tafel slope of 56 mV dec^-(1) and a 60 hlasting stability in alkaline media.The OER kinetics are greatly expedited with a low reaction activation energy of 27.9 kJ mol^-(1) as well as abundant OOH*key intermediates(24%),thus exhibiting excellent catalytic performances.The surface electron-deficient engineering gives an available strategy to improve the catalytic activity of other advanced non-noble electrocatalysts.
基金financially supported by the National Natural Science Foundation of China for Innovative Research Groups (No. 51621002)the National Key Research and Development Program of China (Grant No. 2016YFA0203700)+5 种基金NSFC (Grant No 51672083)Program of Shanghai Academic/Technology Research Leader (18XD1401400)Basic Research Program of Shanghai (17JC1404702)Leading talents in Shanghai in 2018The Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, the 111 project (B14018)The Fundamental Research Funds for Central Universities (222201718002)。
文摘The low sulfur utilization and fast capacity fading resulting from the sluggish redox reaction and abominable polysulfides shuttle greatly hinder the practical applications of lithium-sulfur(Li-S) batteries.Herein, we develop a facile "in-situ growth" method to decorate ultra-small Mo2 C nanoparticles(USMo2 C) on the surface of Ketjen Black(KB) to functionalize the commercial polypropylene(PP) separators,which can accelerate the redox kinetics of lithium polysulfides conversion and effectively increase the utilization of sulfur for Li-S batteries. Importantly, the US-Mo2 C nanoparticles have abundant sites for chemical adsorption towards polysulfides and the conductive carbon networks of KB have cross-linked pore channels, which can promote electron transport and provide physical barrier and volume expansion space for polysulfides. Due to the combined effects of the US-Mo2 C and KB, Li-S cells employing the multifunctional PP separators modified with KB/US-Mo2 C composite(KB/US-Mo2 C@PP) exhibit a high specific capacity(1212.8 mAh g^(-1) at 0.2 C), and maintain a reversible capacity of 1053.3 m Ah g^(-1) after 100 cycles.More importantly, the KB/US-Mo2 C@PP cells with higher sulfur mass loading of 4.9 mg cm^(-2) have superb areal capacity of 2.3 mAh cm^(-2). This work offers a novel and promising perspective for high-performance Li-S batteries from both the shuttle effect and the complex polysulfides conversion.
基金supported by the National Natural Science Foundation of China (21975074, 91834301 and 51621002)the Innovation Program of Shanghai Municipal Education Commissionthe Fundamental Research Funds for the Central Universities (222201718002)。
文摘Oxygen vacancies (V_(o)) engineering has been deemed to an effective tactic for enhancing Li-ion storage kinetics and reversibility of SnO_(2)-based anode materials.Herein,we demonstrated the confinement of ultrahigh V_(o)SnO_(2) nanocrystals into N-doped carbon frameworks to boost their high-rate and cycle life.Density functional theory (DFT) calculations reveal that abundant V_(o) in SnO_(2) facilitates the adsorption to Li-ion with remarkably increased carrier concentration.The 6.0 nm-sized SnO_(2) particles and the embedded design effectively stabilize the structural integrity during de-/lithiation.Meantime,the as-formed large hetero-interface also expedites the electron transfer.These merits guarantee its high-rate performance and superior cycling stability.Consequently,this sample exhibits a high capacity of 1368.9m Ah g^(-1)at 0.1 A g^(-1),and can still maintain 488.5 mAh g^(-1)at 10 A g^(-1)and a long life over 400 cycles at 5 A g^(-1)with 96.6%capacity retention,which is among the best report for Sn-contained anode materials.This work sheds light on ultrahigh Vo and structural design in conversion-type oxides for highperformance lithium-ion batteries (LIBs).
基金financially supported by the National Natural Science Funds for Distinguished Young Scholars(51725201)the International(Regional)Cooperation and Exchange Projects of the National Natural Science Foundation of China(51920105003)+4 种基金the Innovation Program of Shanghai Municipal Education Commission(E00014)the Science and Technology Commission of Shanghai Municipality(21DZ1207101)the National Natural Science Foundation of China(21902048)the Shanghai Engineering Research Center of Hierarchical Nanomaterials(18DZ2252400)Additional support was provided by the Feringa Nobel Prize Scientist Joint Research Center。
文摘Surface modification by metal ion has been considered a promising strategy to enhance the photocatalytic activity by extending optical response and improving charge separation and transportation.Here,univalent copper species were modified on ZnIn_(2)S_(4)photocatalyst via an in-situ photodeposition method,exhibiting a much higher H2evolution rate of 41.10±3.43 mmol g^(-1)h^(-1)and an impressive apparent quantum efficiency(AQE)of 20.81%at 420±15 nm.Our characterizations indicate that the surface modification by copper species can broaden light utilization as well as promote charge separation and transportation.Besides,the density functional theory(DFT)results further exhibit that the energy levels(LUMO and HOMO)for copper-surface modified ZnIn_(2)S_(4)present spatial separation,locating on the Zn-S and In-S layers,respectively,which can suppress the recombination of electron and hole and thus achieves higher photocatalytic H2evolution efficiency.
基金sponsored by the National Natural Science Foundation of China(61804054)the Natural Science Foundation of Shanghai(18ZR1410400)+2 种基金the Shanghai Sailing Program(17YF1403300)the Shanghai Aerospace Science and Technology Innovation Fundation(SISP2018)the Shanghai Aerospace Science and Technology Innovation Fund(SAST2019-067)。
文摘Flexible aqueous Ni//Zn batteries have attracted much attention as promising candidates for energy storage in the field of flexible electronics.However,the Ni-based cathodes still face the challenges of poor conductivity,confined charge/mass transfer,and non-flexibility.In this work,we designed a hollow tubular structure consisting of a conductive silver nanowire (Ag NW) wrapped by active Ni Co layered double hydroxide (LDH),for enhancing the electrical conductivity,improving the charge/mass transfer kinetics,and facilitating the ion penetration.By optimizing the contents of Ni,Co and Ag NW,the Ni_(4)Co LDH@Ag_(1.5)NW composite shows a maximum specific capacity of 115.83 m Ah g^(-1)at 0.1 A g^(-1)measured in a two-electrode system.Highlightingly,the flexible aqueous Ni//Zn battery assembled by Ni_(4)Co LDH@Ag_(1.5)NW interwoven with multi-walled carbon nanotube cathode and Zn foil anode realizes a high power density of 160μW cm^(-2)at the energy density of 23.14μWh cm^(-2),which is superior compared with those of oxide/hydroxide based devices and even higher than those of many carbon-based supercapacitors,showing its promising potentials for flexible energy storage applications.
基金supported by the National Natural Science Foundation of China(21522602, 51672082, 91534202)the International Science and Technology Cooperation Program of China (2015DFA51220)+2 种基金the Research Project of Chinese Ministry of Education(113026A)the Program for Shanghai Youth Top-notch Talentthe Fundamental Research Funds for the Central Universities
文摘Searching for efficient and robust non-noble electrocatalysts for hydrogen generation is extremely desirable for future green energy systems.Here, we present the synthesis of integrated Ni-P-S nanosheets array including Ni_2P and NiS on nickel foam by a simple simultaneous phosphorization and sulfurization strategy. The resultant sample with optimal composition exhibits superior electrocatalytic performance for hydrogen evolution reaction(HER) in a wide pH range. In alkaline media, it can generate current densities of 10, 20 and 100 mA cm^(-2) at low overpotentials of only-101.9,-142.0 and-207.8 mV with robust durability. It still exhibits high electrocatalytic activities even in acid or neutral media. Such superior electrocatalytic performances can be mainly attributed to the synergistic enhancement of the hybrid Ni-P-S nanosheets array with integration microstructure. The kind of catalyst gives a new insight on achieving efficient and robust hydrogen generation.
