Iron-chromium redox flow batteries(ICRFBs)have emerged as promising energy storage devices due to their safety,environmental protection,and reliable performance.The carbon cloth(CC),often used in ICRFBs as the electro...Iron-chromium redox flow batteries(ICRFBs)have emerged as promising energy storage devices due to their safety,environmental protection,and reliable performance.The carbon cloth(CC),often used in ICRFBs as the electrode,provides a suitable platform for electrochemical processes owing to its high surface area and interconnected porous structure.However,the CC electrodes have issues,such as,insufficient electron transfer performance,which limits their industrial application.Here,we employed silicic acid etching to carve dense nano-porous structures on the surface of CC electrodes based on the favorable design of ICRFBs and the fundamental principles of electrode polarization losses.As a result,we developed a multifunctional carbon cloth electrode with abundant vacancies,notably enhancing the performance of the battery.The fabricated electrode showcased a wealth of defect sites and superior electronic transport properties,offering an extensive and effective reaction area for rapidly flowing electrolytes.With an electrode compression ratio of 40%and the highest current density in ICRFBs so far(140 mA·cm^(-2)),the battery achieved the average energy efficiency of 81.3%,11.24%enhancement over the previously published work.Furthermore,throughout 100 charge-discharge cycles,the average energy efficiency degradation was negligible(~0.04%),which has the potential to become the most promising candidate for large-scale and long-term electrochemical energy storage applications.展开更多
Defect sites on oxide semiconductors play a crucial role in promoting photocatalytiperformance and mod-ulating the bandgap structure of photocatalysts.However,the role of interfacial coordinatively unsatu-rated defect...Defect sites on oxide semiconductors play a crucial role in promoting photocatalytiperformance and mod-ulating the bandgap structure of photocatalysts.However,the role of interfacial coordinatively unsatu-rated defect sites between metal and oxide in photocatalysis is still under debate.So,we designed an experiment to probe the role of interfacial coordinatively unsaturated defect sites.In this work,a se-ries of Ti/TiO_(2) photocatalysts with varying concentrations of interfacial Ti^(3+)sites were prepared through an epitaxial growth method under hydrothermal conditions.Through experimental and computational investigations,the roles of interfacial defect sites were discussed in detail.On the one hand,the inter-facial coordinatively unsaturated Ti^(3+)sites could act as visible-light-responsive sites in photocatalytic reactions due to the overlap and hybridization of multiple electronic orbitals.On the other hand,the Ti/TiO_(2) interface exhibited a certain degree of metallic character near the Fermi level because of the par-tial delocalization and redistribution of electrons,facilitating the charge migration and separation across the metal-oxide interface.Consequently,the obtained Ti/TiO_(2) catalysts showed notably enhanced charge transfer efficiency and visible light photocatalytic activity compared to their pristine counterparts.This work may provide a new perspective to interfacial defect engineering in classic metal/oxide heterojunc-tion photocatalysts and figure a more precise direction to synthesize higher effective photocatalysts for environmental governance.展开更多
Electrochemical reduction of CO_(2) to fuels and chemicals is a viable strategy for CO_(2) utilization and renewable energy storage.Developing free-standing electrodes from robust and scalable electrocatalysts becomes...Electrochemical reduction of CO_(2) to fuels and chemicals is a viable strategy for CO_(2) utilization and renewable energy storage.Developing free-standing electrodes from robust and scalable electrocatalysts becomes highly desirable.Here,dense SnO_(2) nanoparticles are uniformly grown on three-dimensional(3D)fiber network of carbon cloth(CC)by a facile dip-coating and calcination method.Importantly,Zn modification strategy is employed to restrain the growth of long-range order of SnO_(2) lattices and to produce rich grain boundaries.The hybrid architecture can act as a flexible electrode for CO_(2)-to-formate conversion,which delivers a high partial current of 18.8 m A cm-2 with a formate selectivity of 80%at a moderate cathodic potential of-0.947 V vs.RHE.The electrode exhibits remarkable stability over a 16 h continuous operation.The superior performance is attributed to the synergistic effect of ultrafine SnO_(2) nanoparticles with abundant active sites and 3D fiber network of the electrode for efficient mass transport and electron transfer.The sizeable electrodes hold promise for industrial applications.展开更多
The reticular chemistry strategy presents a powerful molecule-design tool to tailor the physical and chemical properties of metal-organic framework(MOF).In this work,we for the first time investigated the effect of or...The reticular chemistry strategy presents a powerful molecule-design tool to tailor the physical and chemical properties of metal-organic framework(MOF).In this work,we for the first time investigated the effect of organic ligands on the radionuclide sequestration(TcO_(4)^(-))of thorium-organic framework.Through a coordination modulation technique,two novel isoreticular thorium-organic frameworks,namely Th-MOF-67 and Th-MOF-68,were obtained.Relative to the antetype MOF of Th-MOF-66 that shows extremely low uptake of ReO_(4)^(-)(a chemical surrogate of radioactive TcO_(4)^(-)),the isoreticular MOFs of Th-MOF-67 and Th-MOF-68 enable ultrahigh uptake of ReO_(4)^(-),giving an impressively 36.8-fold or 56-fold enhancement,respectively.The adsorption capacity of Th-MOF-68 is as high as 560 mg/g,exceeding most reported adsorbents for such use.The mechanism for such exceptional outstanding performance,as unveiled by both the single crystal X-ray diffraction and theoretical calculation,is due to coordination interaction for Th-MOF-67,when a tetrazolate ligand was used,or a combined effect from both coordination interaction and anion-exchange for Th-MOF-68,if using a triazolate ligand.展开更多
基金the National Natural Science Foundation of China(Nos.22308378,22308380,52211530034).
文摘Iron-chromium redox flow batteries(ICRFBs)have emerged as promising energy storage devices due to their safety,environmental protection,and reliable performance.The carbon cloth(CC),often used in ICRFBs as the electrode,provides a suitable platform for electrochemical processes owing to its high surface area and interconnected porous structure.However,the CC electrodes have issues,such as,insufficient electron transfer performance,which limits their industrial application.Here,we employed silicic acid etching to carve dense nano-porous structures on the surface of CC electrodes based on the favorable design of ICRFBs and the fundamental principles of electrode polarization losses.As a result,we developed a multifunctional carbon cloth electrode with abundant vacancies,notably enhancing the performance of the battery.The fabricated electrode showcased a wealth of defect sites and superior electronic transport properties,offering an extensive and effective reaction area for rapidly flowing electrolytes.With an electrode compression ratio of 40%and the highest current density in ICRFBs so far(140 mA·cm^(-2)),the battery achieved the average energy efficiency of 81.3%,11.24%enhancement over the previously published work.Furthermore,throughout 100 charge-discharge cycles,the average energy efficiency degradation was negligible(~0.04%),which has the potential to become the most promising candidate for large-scale and long-term electrochemical energy storage applications.
基金financialy supported by the National Key Research and Development Plan of China (No.2016YFC0209305)the Science and Technology Plans of Tianjin (No.18PTZWHZ00180)+1 种基金the Major National Science and Technology Projects (No.2017ZX07106001)the Tianjin Development Program for Innovation and Entrepreneurship。
文摘Defect sites on oxide semiconductors play a crucial role in promoting photocatalytiperformance and mod-ulating the bandgap structure of photocatalysts.However,the role of interfacial coordinatively unsatu-rated defect sites between metal and oxide in photocatalysis is still under debate.So,we designed an experiment to probe the role of interfacial coordinatively unsaturated defect sites.In this work,a se-ries of Ti/TiO_(2) photocatalysts with varying concentrations of interfacial Ti^(3+)sites were prepared through an epitaxial growth method under hydrothermal conditions.Through experimental and computational investigations,the roles of interfacial defect sites were discussed in detail.On the one hand,the inter-facial coordinatively unsaturated Ti^(3+)sites could act as visible-light-responsive sites in photocatalytic reactions due to the overlap and hybridization of multiple electronic orbitals.On the other hand,the Ti/TiO_(2) interface exhibited a certain degree of metallic character near the Fermi level because of the par-tial delocalization and redistribution of electrons,facilitating the charge migration and separation across the metal-oxide interface.Consequently,the obtained Ti/TiO_(2) catalysts showed notably enhanced charge transfer efficiency and visible light photocatalytic activity compared to their pristine counterparts.This work may provide a new perspective to interfacial defect engineering in classic metal/oxide heterojunc-tion photocatalysts and figure a more precise direction to synthesize higher effective photocatalysts for environmental governance.
基金supported by the National Natural Science Foundation of China(51902204,22003041,21975163)Bureau of Industry and Information Technology of Shenzhen(201901171518)Shenzhen Science and Technology Program(KQTD20190929173914967)。
文摘Electrochemical reduction of CO_(2) to fuels and chemicals is a viable strategy for CO_(2) utilization and renewable energy storage.Developing free-standing electrodes from robust and scalable electrocatalysts becomes highly desirable.Here,dense SnO_(2) nanoparticles are uniformly grown on three-dimensional(3D)fiber network of carbon cloth(CC)by a facile dip-coating and calcination method.Importantly,Zn modification strategy is employed to restrain the growth of long-range order of SnO_(2) lattices and to produce rich grain boundaries.The hybrid architecture can act as a flexible electrode for CO_(2)-to-formate conversion,which delivers a high partial current of 18.8 m A cm-2 with a formate selectivity of 80%at a moderate cathodic potential of-0.947 V vs.RHE.The electrode exhibits remarkable stability over a 16 h continuous operation.The superior performance is attributed to the synergistic effect of ultrafine SnO_(2) nanoparticles with abundant active sites and 3D fiber network of the electrode for efficient mass transport and electron transfer.The sizeable electrodes hold promise for industrial applications.
基金supported financially by the Natural Science Foundation of Jiangxi Province of China(No.20181ACB20003)the Training Program for Academic and Technical Leaders of Major Disciplines in Jiangxi Province(No.20194BCJ22010)the National Natural Science Foundations of China(Nos.21966002 and 21871047).
文摘The reticular chemistry strategy presents a powerful molecule-design tool to tailor the physical and chemical properties of metal-organic framework(MOF).In this work,we for the first time investigated the effect of organic ligands on the radionuclide sequestration(TcO_(4)^(-))of thorium-organic framework.Through a coordination modulation technique,two novel isoreticular thorium-organic frameworks,namely Th-MOF-67 and Th-MOF-68,were obtained.Relative to the antetype MOF of Th-MOF-66 that shows extremely low uptake of ReO_(4)^(-)(a chemical surrogate of radioactive TcO_(4)^(-)),the isoreticular MOFs of Th-MOF-67 and Th-MOF-68 enable ultrahigh uptake of ReO_(4)^(-),giving an impressively 36.8-fold or 56-fold enhancement,respectively.The adsorption capacity of Th-MOF-68 is as high as 560 mg/g,exceeding most reported adsorbents for such use.The mechanism for such exceptional outstanding performance,as unveiled by both the single crystal X-ray diffraction and theoretical calculation,is due to coordination interaction for Th-MOF-67,when a tetrazolate ligand was used,or a combined effect from both coordination interaction and anion-exchange for Th-MOF-68,if using a triazolate ligand.
