Accelerating the sluggish redox kinetics of lithium polysulfides(LiPSs)by electrocatalysis is essential to achieve high performance lithium-sulfur(Li-S)batteries.However,the issue of insufficient catalytic activity re...Accelerating the sluggish redox kinetics of lithium polysulfides(LiPSs)by electrocatalysis is essential to achieve high performance lithium-sulfur(Li-S)batteries.However,the issue of insufficient catalytic activity remains to be addressed.Herein,a strategy of modulating e_(g) orbitals through ligand engineering has been proposed to boost the catalytic activity of NiSe for rapid LiPSs redox conversion.The X-ray spectroscopic measurements and theoretical calculations reveal that partial substitution of Se with N disrupts the octahedral coordination of Ni atoms in NiSe,leading to the reduced degeneracy and upward shift of e_(g) orbitals of Ni 3 d states.As a consequence,the bonding strength of N-substituted NiSe(N-NiSe)with LiPSs is enhanced,which facilitates the interfacial charge transfer kinetics and accelerates the LiPSs redox kinetics.Therefore,the Li-S batteries assembled with N-NiSe present a high capacity of 682.6 mAh g^(-1) at a high rate of 5 C and a high areal capacity of 6.5 mAh cm^(-2)at a high sulfur loading of 6 mg cm^(-2).This work provides a promising strategy to develop efficient transition-metal based electrocatalysts for Li-S batteries through e_(g) orbital modulation.展开更多
Lead halide perovskite nanocrystals(PNCs)have received great research interests due to their excellent optoelectronic properties.However,high temperature,inert gas protection and insulating long-chain ligands are used...Lead halide perovskite nanocrystals(PNCs)have received great research interests due to their excellent optoelectronic properties.However,high temperature,inert gas protection and insulating long-chain ligands are used during the conventional hot-injection synthesis of PNCs,which limits their practical applications.In this work,we first develop a simple and scalable polar-solvent-free method for the preparation of full-component APbX_(3)(A=Cs,methylammonium(MA),formamidinium(FA),X=Cl,Br,I)PNCs under ambient condition.Through an exothermic reaction between butylamine(BA)and propionic acid(PA)short ligands,the PbX_(2) precursors could be well dissolved without use of any polar solvent.Meanwhile,the relatively lower growth rate of PNCs in our room-temperature reaction enables us to modulate the synthetic procedure to enhance the scalability(40-fold)and achieve large-scale synthesis.The resultant short ligands passivated PNC inks are compatible with varying solution depositing technique like spray coating for large-area film.Finally,we showcase that adopting the as-prepared MAPbI_(3) PNC inks,a self-powered photodetector is fabricated and shows a high photoresponsivity.These results demonstrate that our ambient-condition synthetic approach can accelerate the preparation of tunable and ready-to-use PNCs towards commercial optoelectronic applications.展开更多
Developing cost-effective,robust and stable non-precious metal catalysts for oxygen reduction reaction(ORR) is of paramount importance for electrochemical energy conversion devices such as fuel cells and metal-air bat...Developing cost-effective,robust and stable non-precious metal catalysts for oxygen reduction reaction(ORR) is of paramount importance for electrochemical energy conversion devices such as fuel cells and metal-air batteries.Although Fe-N-C single atom catalysts(SACs) have been hailed as the most promising candidate due to the optimal binding strength of ORR intermediates on the Fe-N_(4) sites,they suffer from serious mass transport limitations as microporous templates/substrates,i.e.,zeolitic imidazolate frameworks(ZIFs),are usually employed to host the active sites.Motivated by this challenge,we herein develop a hydrogen-bonded organic framework(HOF)-assisted pyrolysis strategy to construct hierarchical micro/mesoporous carbon nanoplates for the deposition of atomically dispersed Fe-N_(4) sites.Such a design is accomplished by employing HOF nanoplates assembled from 2-aminoterephthalic acid(NH_(2)-BDC) and p-phenylenediamine(PDA) as both soft templates and C,N precursors.Benefitting from the structural merits inherited from HOF templates,the optimized catalyst(denoted as Fe-N-C SAC-950) displays outstanding ORR activity with a high half-wave potential of 0.895 V(vs.reversible hydrogen electrode(RHE)) and a small overpotential of 356 mV at 10 mA cm^(-2) for the oxygen evolution reaction(OER).More excitingly,its application potential is further verified by delivering superb rechargeability and cycling stability with a nearly unfading charge-discharge gap of 0.72 V after 160 h.Molecular dynamics(MD) simulations reveal that micro/mesoporous structure is conducive to the rapid mass transfer of O_(2),thus enhancing the ORR performance.In situ Raman results further indicate that the conversion of O_(2) to~*O_(2)-the rate-determining step(RDS) for Fe-N-C SAC-950.This work will provide a versatile strategy to construct single atom catalysts with desirable catalytic properties.展开更多
As a highly tempting technology to close the carbon cycle,electrochemical CO_(2)reduction calls for the development of highly efficient and durable electrocatalysts.In the current study,Design of Experiments utilizing...As a highly tempting technology to close the carbon cycle,electrochemical CO_(2)reduction calls for the development of highly efficient and durable electrocatalysts.In the current study,Design of Experiments utilizing the response surface method is exploited to predict the optimal process variables for preparing high-performance Cu catalysts,unraveling that the selectivity towards methane or ethylene can be simply modulated by varying the evaporation parameters,among which the Cu film thickness is the most pivotal factor to determine the product selectivity.The predicted optimal catalyst with a low Cu thickness affords a high methane Faradaic efficiency of 70.6%at the partial current density of 211.8 m A cm^(-2),whereas that of a high Cu thickness achieves a high ethylene selectivity of 66.8%at267.2 m A cm^(-2)in the flow cell.Further structure-performance correlation and in-situ electrospectroscopic measurements attribute the high methane selectivity to isolated Cu clusters with low packing density and monotonous lattice structure,and the high ethylene efficiency to coalesced Cu nanoparticles with rich grain boundaries and lattice defects.The high Cu packing density and crystallographic diversity is of essence to promoting C–C coupling by stabilizing*CO and suppressing*H coverage on the catalyst surface.This work highlights the implementation of scientific and mathematic methods to uncover optimal catalysts and mechanistic understandings toward selective electrochemical CO_(2)reduction.展开更多
Reconstruction during the catalytic process has been considered to play a key role for the performance.Here we report a RuNiPO based catalyst for efficient alkaline hydrogen evolution reaction(HER),which can benefit f...Reconstruction during the catalytic process has been considered to play a key role for the performance.Here we report a RuNiPO based catalyst for efficient alkaline hydrogen evolution reaction(HER),which can benefit from a long-term reconstruction during HER for 10 h to continuously increase the performance.The final catalyst(e-RuNiPO)shows a huge morphology change from bulk sphere to highly exposed layered structure in the electrocatalysis process,and exhibits an interesting electronic structure modification with the electron transfer from Ru to Ni for better interfacial interaction and quick charge transfer.Due to the favorable morphology with more exposed active sites and the optimized electronic structure,the final catalyst can achieve an outstanding performance with only an overpotential of 15 mV at 10 mA cm^(-2)(with a good stability more than 100 h),even outperforming the performance of benchmark 20 wt%Pt/C catalyst(18 mV at 10 mA cm^(-2))by using a much lower Ru content.展开更多
Nonfullerene organic solar cells(OSCs) and photodetectors have received tremendous interest due to their rapidly progressed power conversion efficiency(PCE) and wide range photoresponse to nearinfrared region, respect...Nonfullerene organic solar cells(OSCs) and photodetectors have received tremendous interest due to their rapidly progressed power conversion efficiency(PCE) and wide range photoresponse to nearinfrared region, respectively. Further optimization of the interfacial transport layer is one of the key factors toward enhanced performance. Herein, we reported a general multi-component electron transport layer(ETL) strategy to achieve better energy level alignments and interfacial contact for both OSCs and photodetectors. The binary polymer:molecule blend based ETL can overcome low crystallinity and selfaggregation issue in neat polymer and molecule ETL, respectively. The mixed blend provides a more tunable platform to optimize the interfacial morphology and creates more efficient charge-transporting pathways. We showcase that the PNDIT-F3N:PDINN binary ETL exhibits its strength in a series of nonfullerene OSCs with enhanced fill factor and current density, achieving a champion PCE approaching 19%. Additionally, self-powered organic photodetectors with lower dark current and high detectivity were achieved with the same binary ETL strategy. Detailed morphology and device characterizations reveal that the binary ETL modulates the interfacial interface to deliver a more favorable energy level alignment, facilitating carrier extraction and transport. We believe these findings could provide insight into the design of ETL with sufficient interfacial tunability for organic optoelectronic devices.展开更多
Highly efficient and green ammonia production is an important demand for modern agriculture.In this study,a two-step ammonia production method is developed using a gliding arc discharge in combination with Cu/Cu_(2)O ...Highly efficient and green ammonia production is an important demand for modern agriculture.In this study,a two-step ammonia production method is developed using a gliding arc discharge in combination with Cu/Cu_(2)O electrocatalysis.In this method,NO_(x)is provided by the gliding arc discharge and then electrolyzed by Cu/Cu_(2)O after alkaline absorption.The electrical characteristics,the optical characteristics and the NO_(x)production are investigated in discharges at different input voltage and the gas flow.The dependence of ammonia production through Cu/Cu_(2)O electrocatalysis on pH value and reduction potential are determined by colorimetric method.In our study,two discharge modes are observed.At high input voltage and low gas flow,the discharge is operated with a stable plasma channel which is called the steady arc gliding discharge mode(A-G mode).As lowering input voltage and raising gas flow,the plasma channel is destroyed and high frequency breakdown occurs instead,which is known as the breakdown gliding discharge mode(B-G mode).The optimal NO_(x)production of 7.34 mmol h^(-1)is obtained in the transition stage of the two discharge modes.The ammonia yield reaches0.402 mmol h^(-1)cm^(-2)at pH value of 12.7 and reduction potential of-1.0 V versus reversible hydrogen electrode(RHE).展开更多
O3-type layered oxides have garnered great attention as cathode materials for sodium-ion batteries because of their abundant reserves and high theoretical capacity.However,challenges persist in the form of uncontrolla...O3-type layered oxides have garnered great attention as cathode materials for sodium-ion batteries because of their abundant reserves and high theoretical capacity.However,challenges persist in the form of uncontrollable phase transitions and intricate Na^(+)diffusion pathways during cycling,resulting in compromised structural stability and reduced capacity over cycles.This study introduces a special approach employing site-specific Ca/F co-substitution within the layered structure of O_(3)-NaNi_(0.5)Mn_(0.5)O_(2) to effectively address these issues.Herein,the strategically site-specific doping of Ca into Na sites and F into O sites not only expands the Na^(+)diffusion pathways but also orchestrates a mild phase transition by suppressing the Na^(+)/vacancy ordering and providing strong metal-oxygen bonding strength,respectively.The as-synthesized Na_(0.95)Ca_(0.05)Ni_(0.5)Mn_(0.5)O_(1.95)F_(0.05)(NNMO-CaF)exhibits a mild O3→O3+O'3→P3 phase transition with minimized interlayer distance variation,leading to enhanced structural integrity and stability over extended cycles.As a result,NNMO-CaF delivers a high specific capacity of 119.5 mA h g^(-1)at a current density of 120 mA g^(-1)with a capacity retention of 87.1%after 100 cycles.This study presents a promising strategy to mitigate the challenges posed by multiple phase transitions and augment Na^(+)diffusion kinetics,thus paving the way for high-performance layered cathode materials in sodium-ion batteries.展开更多
The discharge and plasma characteristics of Ag magnetron sputtering discharge operated near the electron series resonance(ESR)oscillation,which was excited using the driving frequency of 27.12 MHz,was investigated.The...The discharge and plasma characteristics of Ag magnetron sputtering discharge operated near the electron series resonance(ESR)oscillation,which was excited using the driving frequency of 27.12 MHz,was investigated.The imaginary part of impedance was found to undergo a transition from capacitive to inductive on varying radio-frequency(RF)power,and the conditions for the ESR excitation were satisfied.The current–voltage(I–V)characteristic of discharge showed that the lower discharge voltage with higher current was an important feature of RF magnetron sputtering operated near the ESR oscillation,which was caused by the small impedance Z originated from the mutual compensation between the sheath capacitive reactance and the plasma inductive reactance.The higher electron temperature,ion flux density and ion energy as well as the moderate electron density were obtained.The interaction of higher energy ions on substrate surface improved the crystallographic quality of Ag films.Therefore,the 27.12 MHz magnetron sputtering operated near the ESR oscillation has better deposition characteristics than that of commercial 13.56 MHz RF magnetron sputtering.展开更多
All-inorganic CsPbI_3 quantum dots(QDs) have demonstrated promising potential in photovoltaic(PV) applications. However, these colloidal perovskites are vulnerable to the deterioration of surface trap states, leading ...All-inorganic CsPbI_3 quantum dots(QDs) have demonstrated promising potential in photovoltaic(PV) applications. However, these colloidal perovskites are vulnerable to the deterioration of surface trap states, leading to a degradation in efficiency and stability. To address these issues, a facile yet effective strategy of introducing hydroiodic acid(HI) into the synthesis procedure is established to achieve high-quality QDs and devices. Through an in-depth experimental analysis, the introduction of HI was found to convert PbI_2 into highly coordinated [PbI_m]~(2-m), enabling control of the nucleation numbers and growth kinetics. Combined optical and structural investigations illustrate that such a synthesis technique is beneficial for achieving enhanced crystallinity and a reduced density of crystallographic defects. Finally, the effect of HI is further reflected on the PV performance. The optimal device demonstrated a significantly improved power conversion efficiency of 15.72% along with enhanced storage stability. This technique illuminates a novel and simple methodology to regulate the formed species during synthesis, shedding light on ofurther understanding solar cell performance, and aiding the design of future novel synthesis protocols for high-performance optoelectronic devices.展开更多
Organic lasers that emit light in the deep-red and near-infrared(NIR)region are of essential importance in laser communication,night vision,bioimaging,and information-secured displays but are still challenging because...Organic lasers that emit light in the deep-red and near-infrared(NIR)region are of essential importance in laser communication,night vision,bioimaging,and information-secured displays but are still challenging because of the lack of proper gain materials.Herein,a new molecular design strategy that operates by merging two excited-state intramolecular proton transfer-active molecules into one excited-state double proton transfer(ESDPT)-active molecule was demonstrated.Based on this new strategy,three new materials were designed and synthesized with two groups of intramolecular resonance-assisted hydrogen bonds,in which the ESDPT process was proven to proceed smoothly based on theoretical calculations and experimental results of steady-state and transient spectra.Benefiting from the effective six-level system constructed by the ESDPT process,all newly designed materials showed low threshold laser emissions at approximately 720 nm when doped in PS microspheres,which in turn proved the existence of the second proton transfer process.More importantly,our well-developed NIR organic lasers showed high laser stability,which can maintain high laser intensity after 12000 pulse lasing,which is essential in practical applications.This work provides a simple and effective method for the development of NIR organic gain materials and demonstrates the ESDPT mechanism for NIR lasing.展开更多
It is regretful that the data error due to the large number of samples tested.The correct data and figure should be as follows:This correction have no impact on the remainder of the manuscript,the interpretation of th...It is regretful that the data error due to the large number of samples tested.The correct data and figure should be as follows:This correction have no impact on the remainder of the manuscript,the interpretation of the data,or the conclusions reached.The authors would like to apologize for any inconvenience caused.展开更多
The dehydrogenation of alkanes has emerged as a vital complementary process to address the increasing global demand for olefins.A key challenge remains in the construction of novel active centers that offer superior a...The dehydrogenation of alkanes has emerged as a vital complementary process to address the increasing global demand for olefins.A key challenge remains in the construction of novel active centers that offer superior activity,stability,and cost-effectiveness.Herein,tricoordinated cobalt atoms were successfully fabricated through an in-situ ligand-protected synthesis by introducing tungsten atoms into zeolite frameworks.These unsaturated Co species efficiently activate C-H bonds while suppressing C-C bond cleavage,resulting in exceptional catalytic activity and olefin selectivity in both propane and ethane dehydrogenation reactions.The optimized Co_(0.2%)@0.01W-S-1 catalyst demonstrated an impressive propylene formation rate of 15.2 molC_(3H6)gcC h^(-1)at 823 K and an ethylene formation rate of 240.3mol_(C2H4)g_(Co)^(-1)h^(-1)at 913 K,with propylene and ethylene selectivities of 99.0%and 97.5%,respectively.These results not only significantly surpass conventional tetracoordinated Co catalysts but also rival some Pt-based catalysts under similar conditions.Importantly,the catalyst exhibited excellent stability in dehydrogenation reactions,with no significant loss in catalytic activity after five consecutive regeneration cycles.This work offers valuable insights into the design of zeolite-supported non-precious metal catalysts with high activity and durability for efficient alkane dehydrogenation.展开更多
基金supported by the Natural Science Foundation of Jiangsu Province (BK20190814)the National Natural Science Foundation of China (11905154)+4 种基金the Suzhou Science and Technology Project-Prospective Application Research Program(SYG202109)the Gusu innovative and entrepreneurial talent(ZXL2019245)the Collaborative Innovation Center of Suzhou Nano Science&Technologythe 111 ProjectSuzhou Key Laboratory of Functional Nano&Soft Materials,Soochow University-Western University Centre for Synchrotron Radiation Research
文摘Accelerating the sluggish redox kinetics of lithium polysulfides(LiPSs)by electrocatalysis is essential to achieve high performance lithium-sulfur(Li-S)batteries.However,the issue of insufficient catalytic activity remains to be addressed.Herein,a strategy of modulating e_(g) orbitals through ligand engineering has been proposed to boost the catalytic activity of NiSe for rapid LiPSs redox conversion.The X-ray spectroscopic measurements and theoretical calculations reveal that partial substitution of Se with N disrupts the octahedral coordination of Ni atoms in NiSe,leading to the reduced degeneracy and upward shift of e_(g) orbitals of Ni 3 d states.As a consequence,the bonding strength of N-substituted NiSe(N-NiSe)with LiPSs is enhanced,which facilitates the interfacial charge transfer kinetics and accelerates the LiPSs redox kinetics.Therefore,the Li-S batteries assembled with N-NiSe present a high capacity of 682.6 mAh g^(-1) at a high rate of 5 C and a high areal capacity of 6.5 mAh cm^(-2)at a high sulfur loading of 6 mg cm^(-2).This work provides a promising strategy to develop efficient transition-metal based electrocatalysts for Li-S batteries through e_(g) orbital modulation.
基金financially supported by the National Key Research and Development Program of China(No.2023YFE0210000)the National Natural Science Foundation of China(Nos.52261145696,52073198)+5 种基金the China National Postdoctoral Program for Innovative Talents(No.BX20230255)the Natural Science Foundation of Jiangsu Province(No.BK20211598)the Jiangsu Funding Program for Excellent Postdoctoral Talent(No.2023ZB405)the Science and Technology Program of Suzhou(No.ST202219)the“111”projectthe Collaborative Innovation Center of Suzhou Nano Science and Technology,Soochow University。
文摘Lead halide perovskite nanocrystals(PNCs)have received great research interests due to their excellent optoelectronic properties.However,high temperature,inert gas protection and insulating long-chain ligands are used during the conventional hot-injection synthesis of PNCs,which limits their practical applications.In this work,we first develop a simple and scalable polar-solvent-free method for the preparation of full-component APbX_(3)(A=Cs,methylammonium(MA),formamidinium(FA),X=Cl,Br,I)PNCs under ambient condition.Through an exothermic reaction between butylamine(BA)and propionic acid(PA)short ligands,the PbX_(2) precursors could be well dissolved without use of any polar solvent.Meanwhile,the relatively lower growth rate of PNCs in our room-temperature reaction enables us to modulate the synthetic procedure to enhance the scalability(40-fold)and achieve large-scale synthesis.The resultant short ligands passivated PNC inks are compatible with varying solution depositing technique like spray coating for large-area film.Finally,we showcase that adopting the as-prepared MAPbI_(3) PNC inks,a self-powered photodetector is fabricated and shows a high photoresponsivity.These results demonstrate that our ambient-condition synthetic approach can accelerate the preparation of tunable and ready-to-use PNCs towards commercial optoelectronic applications.
基金financially supported by the National Key R&D Program of China(2022YFB4004100)the National Natural Science Foundation of China(22272161)+6 种基金the Jilin Province Science and Technology Development Program(20230101367JC)financially supported by the National Natural Science Foundation of China(22073094)the Science and Technology Development Program of Jilin Province(20210402059GH)the Science and Technology Plan Projects of Yunnan Province(202101BC070001–007)the Major Science and Technology Projects for Independent Innovation of China FAW Group Co.,Ltd(20220301018GX)the essential support of the Network and Computing Center,CIAC,CASthe Computing Center of Jilin Province。
文摘Developing cost-effective,robust and stable non-precious metal catalysts for oxygen reduction reaction(ORR) is of paramount importance for electrochemical energy conversion devices such as fuel cells and metal-air batteries.Although Fe-N-C single atom catalysts(SACs) have been hailed as the most promising candidate due to the optimal binding strength of ORR intermediates on the Fe-N_(4) sites,they suffer from serious mass transport limitations as microporous templates/substrates,i.e.,zeolitic imidazolate frameworks(ZIFs),are usually employed to host the active sites.Motivated by this challenge,we herein develop a hydrogen-bonded organic framework(HOF)-assisted pyrolysis strategy to construct hierarchical micro/mesoporous carbon nanoplates for the deposition of atomically dispersed Fe-N_(4) sites.Such a design is accomplished by employing HOF nanoplates assembled from 2-aminoterephthalic acid(NH_(2)-BDC) and p-phenylenediamine(PDA) as both soft templates and C,N precursors.Benefitting from the structural merits inherited from HOF templates,the optimized catalyst(denoted as Fe-N-C SAC-950) displays outstanding ORR activity with a high half-wave potential of 0.895 V(vs.reversible hydrogen electrode(RHE)) and a small overpotential of 356 mV at 10 mA cm^(-2) for the oxygen evolution reaction(OER).More excitingly,its application potential is further verified by delivering superb rechargeability and cycling stability with a nearly unfading charge-discharge gap of 0.72 V after 160 h.Molecular dynamics(MD) simulations reveal that micro/mesoporous structure is conducive to the rapid mass transfer of O_(2),thus enhancing the ORR performance.In situ Raman results further indicate that the conversion of O_(2) to~*O_(2)-the rate-determining step(RDS) for Fe-N-C SAC-950.This work will provide a versatile strategy to construct single atom catalysts with desirable catalytic properties.
基金supported by the National Key R&D Program of China(2020YFB1505703)the National Natural Science Foundation of China(22072101,22075193)+2 种基金supported by the Natural Science Foundation of Jiangsu Province(BK20211306)the Six Talent Peaks Project in Jiangsu Province(TD-XCL-006)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions。
文摘As a highly tempting technology to close the carbon cycle,electrochemical CO_(2)reduction calls for the development of highly efficient and durable electrocatalysts.In the current study,Design of Experiments utilizing the response surface method is exploited to predict the optimal process variables for preparing high-performance Cu catalysts,unraveling that the selectivity towards methane or ethylene can be simply modulated by varying the evaporation parameters,among which the Cu film thickness is the most pivotal factor to determine the product selectivity.The predicted optimal catalyst with a low Cu thickness affords a high methane Faradaic efficiency of 70.6%at the partial current density of 211.8 m A cm^(-2),whereas that of a high Cu thickness achieves a high ethylene selectivity of 66.8%at267.2 m A cm^(-2)in the flow cell.Further structure-performance correlation and in-situ electrospectroscopic measurements attribute the high methane selectivity to isolated Cu clusters with low packing density and monotonous lattice structure,and the high ethylene efficiency to coalesced Cu nanoparticles with rich grain boundaries and lattice defects.The high Cu packing density and crystallographic diversity is of essence to promoting C–C coupling by stabilizing*CO and suppressing*H coverage on the catalyst surface.This work highlights the implementation of scientific and mathematic methods to uncover optimal catalysts and mechanistic understandings toward selective electrochemical CO_(2)reduction.
基金supported by the National Key R&D Program of China(2020YFA0406103)the National Natural Science Foundation of China(U1932211,12205213)+2 种基金the Jiangsu Planned Projects for Postdoctoral Research Funds(7121453621)the Collaborative Innovation Center of Suzhou Nano Science&Technology,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the 111 Project。
文摘Reconstruction during the catalytic process has been considered to play a key role for the performance.Here we report a RuNiPO based catalyst for efficient alkaline hydrogen evolution reaction(HER),which can benefit from a long-term reconstruction during HER for 10 h to continuously increase the performance.The final catalyst(e-RuNiPO)shows a huge morphology change from bulk sphere to highly exposed layered structure in the electrocatalysis process,and exhibits an interesting electronic structure modification with the electron transfer from Ru to Ni for better interfacial interaction and quick charge transfer.Due to the favorable morphology with more exposed active sites and the optimized electronic structure,the final catalyst can achieve an outstanding performance with only an overpotential of 15 mV at 10 mA cm^(-2)(with a good stability more than 100 h),even outperforming the performance of benchmark 20 wt%Pt/C catalyst(18 mV at 10 mA cm^(-2))by using a much lower Ru content.
基金financially supported by the National Key Research and Development Program of China (No.2023YFE0210000)the National Natural Science Foundation of China (No. 52261145696, and 52073198)+2 种基金the ‘‘111” projectthe Young Elite Scientist Sponsorship Program by CASTthe Collaborative Innovation Center of Suzhou Nano Science and Technology,Soochow University。
文摘Nonfullerene organic solar cells(OSCs) and photodetectors have received tremendous interest due to their rapidly progressed power conversion efficiency(PCE) and wide range photoresponse to nearinfrared region, respectively. Further optimization of the interfacial transport layer is one of the key factors toward enhanced performance. Herein, we reported a general multi-component electron transport layer(ETL) strategy to achieve better energy level alignments and interfacial contact for both OSCs and photodetectors. The binary polymer:molecule blend based ETL can overcome low crystallinity and selfaggregation issue in neat polymer and molecule ETL, respectively. The mixed blend provides a more tunable platform to optimize the interfacial morphology and creates more efficient charge-transporting pathways. We showcase that the PNDIT-F3N:PDINN binary ETL exhibits its strength in a series of nonfullerene OSCs with enhanced fill factor and current density, achieving a champion PCE approaching 19%. Additionally, self-powered organic photodetectors with lower dark current and high detectivity were achieved with the same binary ETL strategy. Detailed morphology and device characterizations reveal that the binary ETL modulates the interfacial interface to deliver a more favorable energy level alignment, facilitating carrier extraction and transport. We believe these findings could provide insight into the design of ETL with sufficient interfacial tunability for organic optoelectronic devices.
文摘Highly efficient and green ammonia production is an important demand for modern agriculture.In this study,a two-step ammonia production method is developed using a gliding arc discharge in combination with Cu/Cu_(2)O electrocatalysis.In this method,NO_(x)is provided by the gliding arc discharge and then electrolyzed by Cu/Cu_(2)O after alkaline absorption.The electrical characteristics,the optical characteristics and the NO_(x)production are investigated in discharges at different input voltage and the gas flow.The dependence of ammonia production through Cu/Cu_(2)O electrocatalysis on pH value and reduction potential are determined by colorimetric method.In our study,two discharge modes are observed.At high input voltage and low gas flow,the discharge is operated with a stable plasma channel which is called the steady arc gliding discharge mode(A-G mode).As lowering input voltage and raising gas flow,the plasma channel is destroyed and high frequency breakdown occurs instead,which is known as the breakdown gliding discharge mode(B-G mode).The optimal NO_(x)production of 7.34 mmol h^(-1)is obtained in the transition stage of the two discharge modes.The ammonia yield reaches0.402 mmol h^(-1)cm^(-2)at pH value of 12.7 and reduction potential of-1.0 V versus reversible hydrogen electrode(RHE).
基金supported by the Science and Technology Program of Suzhou(ST202304)the National Natural Science Foundation of China(12275189)+1 种基金the Collaborative Innovation Center of Suzhou Nano Science&Technologythe 111 project。
文摘O3-type layered oxides have garnered great attention as cathode materials for sodium-ion batteries because of their abundant reserves and high theoretical capacity.However,challenges persist in the form of uncontrollable phase transitions and intricate Na^(+)diffusion pathways during cycling,resulting in compromised structural stability and reduced capacity over cycles.This study introduces a special approach employing site-specific Ca/F co-substitution within the layered structure of O_(3)-NaNi_(0.5)Mn_(0.5)O_(2) to effectively address these issues.Herein,the strategically site-specific doping of Ca into Na sites and F into O sites not only expands the Na^(+)diffusion pathways but also orchestrates a mild phase transition by suppressing the Na^(+)/vacancy ordering and providing strong metal-oxygen bonding strength,respectively.The as-synthesized Na_(0.95)Ca_(0.05)Ni_(0.5)Mn_(0.5)O_(1.95)F_(0.05)(NNMO-CaF)exhibits a mild O3→O3+O'3→P3 phase transition with minimized interlayer distance variation,leading to enhanced structural integrity and stability over extended cycles.As a result,NNMO-CaF delivers a high specific capacity of 119.5 mA h g^(-1)at a current density of 120 mA g^(-1)with a capacity retention of 87.1%after 100 cycles.This study presents a promising strategy to mitigate the challenges posed by multiple phase transitions and augment Na^(+)diffusion kinetics,thus paving the way for high-performance layered cathode materials in sodium-ion batteries.
基金supported by National Natural Science Foundation of China (No.11275136)。
文摘The discharge and plasma characteristics of Ag magnetron sputtering discharge operated near the electron series resonance(ESR)oscillation,which was excited using the driving frequency of 27.12 MHz,was investigated.The imaginary part of impedance was found to undergo a transition from capacitive to inductive on varying radio-frequency(RF)power,and the conditions for the ESR excitation were satisfied.The current–voltage(I–V)characteristic of discharge showed that the lower discharge voltage with higher current was an important feature of RF magnetron sputtering operated near the ESR oscillation,which was caused by the small impedance Z originated from the mutual compensation between the sheath capacitive reactance and the plasma inductive reactance.The higher electron temperature,ion flux density and ion energy as well as the moderate electron density were obtained.The interaction of higher energy ions on substrate surface improved the crystallographic quality of Ag films.Therefore,the 27.12 MHz magnetron sputtering operated near the ESR oscillation has better deposition characteristics than that of commercial 13.56 MHz RF magnetron sputtering.
基金financially supported by the National Key Research and Development Program of China (No. 2021YFB3800101 and 2022YFE0110300)National Natural Science Foundation of China (No. U19A2089, 52261145696, 52073198, 92163114, and 22161142003)+3 种基金Natural Science Foundation of Jiangsu Province (BK20211598)“111” projectthe Young Elite Scientist Sponsorship Program by CASTCollaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University。
文摘All-inorganic CsPbI_3 quantum dots(QDs) have demonstrated promising potential in photovoltaic(PV) applications. However, these colloidal perovskites are vulnerable to the deterioration of surface trap states, leading to a degradation in efficiency and stability. To address these issues, a facile yet effective strategy of introducing hydroiodic acid(HI) into the synthesis procedure is established to achieve high-quality QDs and devices. Through an in-depth experimental analysis, the introduction of HI was found to convert PbI_2 into highly coordinated [PbI_m]~(2-m), enabling control of the nucleation numbers and growth kinetics. Combined optical and structural investigations illustrate that such a synthesis technique is beneficial for achieving enhanced crystallinity and a reduced density of crystallographic defects. Finally, the effect of HI is further reflected on the PV performance. The optimal device demonstrated a significantly improved power conversion efficiency of 15.72% along with enhanced storage stability. This technique illuminates a novel and simple methodology to regulate the formed species during synthesis, shedding light on ofurther understanding solar cell performance, and aiding the design of future novel synthesis protocols for high-performance optoelectronic devices.
基金We are grateful for financial supports from the National Natural Science Foundation of China(Nos.52173177,21971185,22105139)Fundação Universidade de Ciência e Tecnologia de Macao(No.0006/2021/AKP)+1 种基金the Natural Science Foundation of Jiangsu Province(No.BK20221362)the Science and Technology Support Program of Jiangsu Province(No.TJ-2022-002).This project is also funded by Suzhou Key Laboratory of Functional Nano&Soft Materials,Collaborative Innovation Center of Suzhou Nano Science&Technology,the 111 Project,Joint International Research Laboratory of Carbon-Based Functional Materials and Devices,and Soochow University Tang Scholar.
文摘Organic lasers that emit light in the deep-red and near-infrared(NIR)region are of essential importance in laser communication,night vision,bioimaging,and information-secured displays but are still challenging because of the lack of proper gain materials.Herein,a new molecular design strategy that operates by merging two excited-state intramolecular proton transfer-active molecules into one excited-state double proton transfer(ESDPT)-active molecule was demonstrated.Based on this new strategy,three new materials were designed and synthesized with two groups of intramolecular resonance-assisted hydrogen bonds,in which the ESDPT process was proven to proceed smoothly based on theoretical calculations and experimental results of steady-state and transient spectra.Benefiting from the effective six-level system constructed by the ESDPT process,all newly designed materials showed low threshold laser emissions at approximately 720 nm when doped in PS microspheres,which in turn proved the existence of the second proton transfer process.More importantly,our well-developed NIR organic lasers showed high laser stability,which can maintain high laser intensity after 12000 pulse lasing,which is essential in practical applications.This work provides a simple and effective method for the development of NIR organic gain materials and demonstrates the ESDPT mechanism for NIR lasing.
文摘It is regretful that the data error due to the large number of samples tested.The correct data and figure should be as follows:This correction have no impact on the remainder of the manuscript,the interpretation of the data,or the conclusions reached.The authors would like to apologize for any inconvenience caused.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1506000)Gusu Innovation and Entrepreneurship Leading Talents Program(ZXL2022497)+5 种基金Jiangsu Distinguished Professor programfinancial support by National Natural Science Foundation of China(Grant No.22301057)Natural Science Foundation of Hebei Province(Grant No.B2023201065)Science Research Project of Hebei Education Department(Grant No.BJK2024103)supported by the Open Research Fund of Shanghai Key Laboratory of High-resolution Electron MicroscopyOpen Project of State Key Laboratory of Supramolecular Structure and Materials(sklssm2024019),ShanghaiTech University。
文摘The dehydrogenation of alkanes has emerged as a vital complementary process to address the increasing global demand for olefins.A key challenge remains in the construction of novel active centers that offer superior activity,stability,and cost-effectiveness.Herein,tricoordinated cobalt atoms were successfully fabricated through an in-situ ligand-protected synthesis by introducing tungsten atoms into zeolite frameworks.These unsaturated Co species efficiently activate C-H bonds while suppressing C-C bond cleavage,resulting in exceptional catalytic activity and olefin selectivity in both propane and ethane dehydrogenation reactions.The optimized Co_(0.2%)@0.01W-S-1 catalyst demonstrated an impressive propylene formation rate of 15.2 molC_(3H6)gcC h^(-1)at 823 K and an ethylene formation rate of 240.3mol_(C2H4)g_(Co)^(-1)h^(-1)at 913 K,with propylene and ethylene selectivities of 99.0%and 97.5%,respectively.These results not only significantly surpass conventional tetracoordinated Co catalysts but also rival some Pt-based catalysts under similar conditions.Importantly,the catalyst exhibited excellent stability in dehydrogenation reactions,with no significant loss in catalytic activity after five consecutive regeneration cycles.This work offers valuable insights into the design of zeolite-supported non-precious metal catalysts with high activity and durability for efficient alkane dehydrogenation.
