Wastewater electrolysis cells(WECs)for decentralized wastewater treatment/reuse coupled with H_(2) production can reduce the carbon footprint associated with transportation of water,waste,and energy carrier.This study...Wastewater electrolysis cells(WECs)for decentralized wastewater treatment/reuse coupled with H_(2) production can reduce the carbon footprint associated with transportation of water,waste,and energy carrier.This study reports Ir-doped NiFe_(2)O_(4)(NFI,~5 at%Ir)spinel layer with TiO_(2) overlayer(NFI/TiO_(2)),as a scalable heterojunction anode for direct electrolysis of wastewater with circumneutral pH in a single-compartment cell.In dilute(0.1 M)NaCl solutions,the NFI/TiO_(2) marks superior activity and selectivity for chlorine evolution reaction,outperforming the benchmark IrO_(2).Robust operation in near-neutral pH was confirmed.Electroanalyses including operando X-ray absorption spectroscopy unveiled crucial roles of TiO_(2) which serves both as the primary site for Cl−chemisorption and a protective layer for NFI as an ohmic contact.Galvanostatic electrolysis of NH4+-laden synthetic wastewater demonstrated that NFI/TiO_(2)not only achieves quasi-stoichiometric NH_(4)^(+)-to-N_(2)conversion,but also enhances H_(2)generation efficiency with minimal competing reactions such as reduction of dissolved oxygen and reactive chlorine.The scaled-up WEC with NFI/TiO_(2)was demonstrated for electrolysis of toilet wastewater.展开更多
Utilizing sunlight to convert CO_(2) into chemical fuels could address the greenhouse effect and fossil fuel crisis,Heterojunction structure catalysts with oxygen vacancy are attractive in the field of photocatalytic ...Utilizing sunlight to convert CO_(2) into chemical fuels could address the greenhouse effect and fossil fuel crisis,Heterojunction structure catalysts with oxygen vacancy are attractive in the field of photocatalytic CO_(2) conversion.Herein,a modified TiO_(2)/In_(2)O_(3)(R-P2 5/In_(2)O_(3-x)) type Ⅱ heterojunction composite with oxygen vacancies is designed for photocatalytic CO_(2) reduction,which exhibits excellent CO_(2) reduction activity,with a C_(2) selectivity of 56.66%(in terms of R_(electron)).In situ Fourier-transform infrared spectroscopy(DRIFTS) and time-resolved photoluminescence(TR-PL) spectroscopy are used to reveal the intermediate formation of the photocatalytic mechanism and photogenerated electron lifetime,respectively.The experimental characterizations reveal that the R-P25/In_(2)O_(3-x) composite shows a remarkable behavior for coupling C-C bonds.Besides,efficient charge separation contributes to the improved CO_(2) conversion performance of photocatalysts.This work introduces a type Ⅱ heterojunction composite photocatalyst,which promotes understanding the CO_(2) reduction mechanisms on heterojunction composites and is valuable for the development of photocatalysts.展开更多
Hydrogen generation and related energy applications heavily rely on the hydrogen evolution reaction(HER),which faces challenges of slow kinetics and high overpotential.Efficient electrocatalysts,particularly single-at...Hydrogen generation and related energy applications heavily rely on the hydrogen evolution reaction(HER),which faces challenges of slow kinetics and high overpotential.Efficient electrocatalysts,particularly single-atom catalysts (SACs) on two-dimensional (2D) materials,are essential.This study presents a few-shot machine learning (ML) assisted high-throughput screening of 2D septuple-atomic-layer Ga_(2)CoS_(4-x)supported SACs to predict HER catalytic activity.Initially,density functional theory (DFT)calculations showed that 2D Ga_(2)CoS4is inactive for HER.However,defective Ga_(2)CoS_(4-x)(x=0–0.25)monolayers exhibit excellent HER activity due to surface sulfur vacancies (SVs),with predicted overpotentials (0–60 mV) comparable to or lower than commercial Pt/C,which typically exhibits an overpotential of around 50 m V in the acidic electrolyte,when the concentration of surface SV is lower than 8.3%.SVs generate spin-polarized states near the Fermi level,making them effective HER sites.We demonstrate ML-accelerated HER overpotential predictions for all transition metal SACs on 2D Ga_(2)CoS_(4-x).Using DFT data from 18 SACs,an ML model with high prediction accuracy and reduced computation time was developed.An intrinsic descriptor linking SAC atomic properties to HER overpotential was identified.This study thus provides a framework for screening SACs on 2D materials,enhancing catalyst design.展开更多
TiNb_(2)O_(7)has been emerged as one of the most promising electrode materials for high-energy lithium-ion batteries.However,limited by the slow electron/ion transport kinetics,and insufficient active sites in the bul...TiNb_(2)O_(7)has been emerged as one of the most promising electrode materials for high-energy lithium-ion batteries.However,limited by the slow electron/ion transport kinetics,and insufficient active sites in the bulk structure,the TiNb_(2)O_(7)electrode still suffers from unsatisfactory lithium storage performance.Herein,we demonstrate a spatially confined strategy toward a novel TiNb_(2)O_(7)-NMC/MXene composite through a triblock copolymer-directed one-pot solvothermal route,where TiNb_(2)O_(7)quantum dots with a particle size of 2-3 nm are evenly embedded into N-doped mesoporous carbon(NMC)and Ti_(3)C_(2)T_(X)MXene.Impressively,the as-prepared TiNb_(2)O_(7)-NMC/MXene anode exhibits a high reversible capacity(486.2 mAh g^(-1)at 0.1 A g^(-1)after 100 cycles)and long cycle lifespan(363.4 mAh g^(-1)at ss1 A g^(-1)after 500 cycles).Both experimental and theorical results further demonstrate that such a superior lithium storage performance is mainly ascribed to the synergistic effect among 0D TiNb_(2)O_(7)quantum dots,2D Ti_(3)C_(2)T_(X)MXene nanosheets,and N-doped mesoporous carbon.The strategy presented also opens up new horizon for space-confined preparation of high-performance electrode materials.展开更多
To improve the electrocatalytic transformation of carbon dioxide (CO_(2)) to multi-carbon (C_(2+)) products is of great importance.Here we developed a nitrogen-doped Cu catalyst,by which the maximum C_(2+) Faradaic ef...To improve the electrocatalytic transformation of carbon dioxide (CO_(2)) to multi-carbon (C_(2+)) products is of great importance.Here we developed a nitrogen-doped Cu catalyst,by which the maximum C_(2+) Faradaic efficiency can reach 72.7%in flow-cell system,with the partial current density reaching 0.62 A cm^(-2).The in situ Raman spectra demonstrate that the *CO adsorption can be strengthened on such a N-doped Cu catalyst,thus promoting the *CO utilization in the subsequent C–C coupling step.Simultaneously,the water activation can be well enhanced by N doping on Cu catalyst.Owing to the synergistic effects,the selectivity and activity for C_(2+) products over the N-deoped Cu catalyst are much improved.展开更多
基金supported by the National Research Foundation of Korea(NRF)grants(2022R1A2C4001228,2022M3H4A4097524,2022M3I3A1082499,and 2021M3I3A1084818)the Technology Innovation Program(20026415)of the Ministry of Trade,Industry&Energy(MOTIE,Korea)the supports from Nanopac for fabrication of scaled-up reactor.
文摘Wastewater electrolysis cells(WECs)for decentralized wastewater treatment/reuse coupled with H_(2) production can reduce the carbon footprint associated with transportation of water,waste,and energy carrier.This study reports Ir-doped NiFe_(2)O_(4)(NFI,~5 at%Ir)spinel layer with TiO_(2) overlayer(NFI/TiO_(2)),as a scalable heterojunction anode for direct electrolysis of wastewater with circumneutral pH in a single-compartment cell.In dilute(0.1 M)NaCl solutions,the NFI/TiO_(2) marks superior activity and selectivity for chlorine evolution reaction,outperforming the benchmark IrO_(2).Robust operation in near-neutral pH was confirmed.Electroanalyses including operando X-ray absorption spectroscopy unveiled crucial roles of TiO_(2) which serves both as the primary site for Cl−chemisorption and a protective layer for NFI as an ohmic contact.Galvanostatic electrolysis of NH4+-laden synthetic wastewater demonstrated that NFI/TiO_(2)not only achieves quasi-stoichiometric NH_(4)^(+)-to-N_(2)conversion,but also enhances H_(2)generation efficiency with minimal competing reactions such as reduction of dissolved oxygen and reactive chlorine.The scaled-up WEC with NFI/TiO_(2)was demonstrated for electrolysis of toilet wastewater.
基金National Research Foundation (NRF) of Korea grant funded by the Korea Government (MSIT) (NRF-2022R1A2C2093415)partially funding from the Circle Foundation (Republic of Korea) (Grant Number: 2023 TCF Innovative Science Project-03))partially Korea Basic Science Institute (National Research Facilities and Equipment Center) grant funded by the Ministry of Education (2022R1A6C101A751)。
文摘Utilizing sunlight to convert CO_(2) into chemical fuels could address the greenhouse effect and fossil fuel crisis,Heterojunction structure catalysts with oxygen vacancy are attractive in the field of photocatalytic CO_(2) conversion.Herein,a modified TiO_(2)/In_(2)O_(3)(R-P2 5/In_(2)O_(3-x)) type Ⅱ heterojunction composite with oxygen vacancies is designed for photocatalytic CO_(2) reduction,which exhibits excellent CO_(2) reduction activity,with a C_(2) selectivity of 56.66%(in terms of R_(electron)).In situ Fourier-transform infrared spectroscopy(DRIFTS) and time-resolved photoluminescence(TR-PL) spectroscopy are used to reveal the intermediate formation of the photocatalytic mechanism and photogenerated electron lifetime,respectively.The experimental characterizations reveal that the R-P25/In_(2)O_(3-x) composite shows a remarkable behavior for coupling C-C bonds.Besides,efficient charge separation contributes to the improved CO_(2) conversion performance of photocatalysts.This work introduces a type Ⅱ heterojunction composite photocatalyst,which promotes understanding the CO_(2) reduction mechanisms on heterojunction composites and is valuable for the development of photocatalysts.
文摘Hydrogen generation and related energy applications heavily rely on the hydrogen evolution reaction(HER),which faces challenges of slow kinetics and high overpotential.Efficient electrocatalysts,particularly single-atom catalysts (SACs) on two-dimensional (2D) materials,are essential.This study presents a few-shot machine learning (ML) assisted high-throughput screening of 2D septuple-atomic-layer Ga_(2)CoS_(4-x)supported SACs to predict HER catalytic activity.Initially,density functional theory (DFT)calculations showed that 2D Ga_(2)CoS4is inactive for HER.However,defective Ga_(2)CoS_(4-x)(x=0–0.25)monolayers exhibit excellent HER activity due to surface sulfur vacancies (SVs),with predicted overpotentials (0–60 mV) comparable to or lower than commercial Pt/C,which typically exhibits an overpotential of around 50 m V in the acidic electrolyte,when the concentration of surface SV is lower than 8.3%.SVs generate spin-polarized states near the Fermi level,making them effective HER sites.We demonstrate ML-accelerated HER overpotential predictions for all transition metal SACs on 2D Ga_(2)CoS_(4-x).Using DFT data from 18 SACs,an ML model with high prediction accuracy and reduced computation time was developed.An intrinsic descriptor linking SAC atomic properties to HER overpotential was identified.This study thus provides a framework for screening SACs on 2D materials,enhancing catalyst design.
基金support from the Natural Science Foundation of Shanghai(23ZR1423800),Shuguang Program supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission(18SG35)Open Research Fund of Shanghai Key Laboratory of Green Chemistry and Chemical Processes(East China Normal University)Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education),Nankai University.
文摘TiNb_(2)O_(7)has been emerged as one of the most promising electrode materials for high-energy lithium-ion batteries.However,limited by the slow electron/ion transport kinetics,and insufficient active sites in the bulk structure,the TiNb_(2)O_(7)electrode still suffers from unsatisfactory lithium storage performance.Herein,we demonstrate a spatially confined strategy toward a novel TiNb_(2)O_(7)-NMC/MXene composite through a triblock copolymer-directed one-pot solvothermal route,where TiNb_(2)O_(7)quantum dots with a particle size of 2-3 nm are evenly embedded into N-doped mesoporous carbon(NMC)and Ti_(3)C_(2)T_(X)MXene.Impressively,the as-prepared TiNb_(2)O_(7)-NMC/MXene anode exhibits a high reversible capacity(486.2 mAh g^(-1)at 0.1 A g^(-1)after 100 cycles)and long cycle lifespan(363.4 mAh g^(-1)at ss1 A g^(-1)after 500 cycles).Both experimental and theorical results further demonstrate that such a superior lithium storage performance is mainly ascribed to the synergistic effect among 0D TiNb_(2)O_(7)quantum dots,2D Ti_(3)C_(2)T_(X)MXene nanosheets,and N-doped mesoporous carbon.The strategy presented also opens up new horizon for space-confined preparation of high-performance electrode materials.
基金supported by National Natural Science Foundation of China (22033009, 22121002, 22238011)。
文摘To improve the electrocatalytic transformation of carbon dioxide (CO_(2)) to multi-carbon (C_(2+)) products is of great importance.Here we developed a nitrogen-doped Cu catalyst,by which the maximum C_(2+) Faradaic efficiency can reach 72.7%in flow-cell system,with the partial current density reaching 0.62 A cm^(-2).The in situ Raman spectra demonstrate that the *CO adsorption can be strengthened on such a N-doped Cu catalyst,thus promoting the *CO utilization in the subsequent C–C coupling step.Simultaneously,the water activation can be well enhanced by N doping on Cu catalyst.Owing to the synergistic effects,the selectivity and activity for C_(2+) products over the N-deoped Cu catalyst are much improved.
