Electrochemical conversion of CO_(2)to CO is an economically feasible method for mitigating greenhouse gas emissions.Among various electrochemical approaches,solid oxide electrolysis cells(SOECs)show high potential fo...Electrochemical conversion of CO_(2)to CO is an economically feasible method for mitigating greenhouse gas emissions.Among various electrochemical approaches,solid oxide electrolysis cells(SOECs)show high potential for CO_(2)reduction reaction(CO_(2)-RR)due to their ability to operate at high temperatures,resulting in fast reaction kinetics and increased efficiency.Considering their main energy loss is still associated with the large overpotential at the fuel electrode,the development of the highly efficient and durable cathode for SOECs has been extensively searched after.Here,we propose an A-site doping strategy to enhance the properties of Sr_(2)Fe_(1.5)Mo_(0.5)O_(6−δ)(SFM),which improve its performance as a cathode in SOECs for CO_(2)-RR,demonstrating favorable activity and durability.The structural and physiochemical characterizations,together with DFT calculations,show that the partial replacement of Sr by Bi in the SFM double perovskite not only improves CO_(2) adsorption capability at the catalyst surface but also enhances oxygen ionic conduction inside the bulk oxide,resulting in enhanced CO_(2)electrocatalysis performance in SOECs.Specifically,a La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.2)O_(3−δ) (LSGM)electrolyte-supported single cell with the new Bi-doped SFM cathode demonstrates a large current density of 1620 mA cm^(−2) at a cell potential of 1.6 V at 850°C with good operational stability up to 200 h.Bi-doped SFM thus represents a highly promising cathode for ceramic CO_(2)electrolyzers and could accelerate our transition towards a carbon-neutral society.展开更多
We report on broadband infrared emission of bismuth-doped RO-B2O3（R=Ca, Sr, Ba） glasses. Glass samples are prepared under various conditions by a conventional melting-quenching method and the luminescence properties...We report on broadband infrared emission of bismuth-doped RO-B2O3（R=Ca, Sr, Ba） glasses. Glass samples are prepared under various conditions by a conventional melting-quenching method and the luminescence properties in infrared wavelength region are investigated. No apparent infrared luminescence is observed in the SrO-B2O3 and BaO-B2O3 prepared in air, while glasses prepared in reducing atmosphere exhibit a broadband infrared luminescence peaking at 1 300 nm with a full width at half maximum（FWHM） of about 200 nm when excited by an 800 nm laser diode. A mechanism was proposed to explain the observed phenomena. The presence of low valence bismuth, probably Bi^＋, is responsible for the broadband infrared emission.展开更多
Nd∶NBW laser crystal with the size of Φ8 mm×20 mm was grown by the process of lifting and pulling. The growth technological parameters which have influence on the completeness of crystal were analyzed and the r...Nd∶NBW laser crystal with the size of Φ8 mm×20 mm was grown by the process of lifting and pulling. The growth technological parameters which have influence on the completeness of crystal were analyzed and the reasonable technological parameters were ascertained.展开更多
Europium-doped bismuth vanadate EBVO-x(0≤x≤7)with different crystalline phases has been successfully synthesized via a simple one-pot hydrothermal method.X-ray diffractometry,Raman scattering and scanning electron m...Europium-doped bismuth vanadate EBVO-x(0≤x≤7)with different crystalline phases has been successfully synthesized via a simple one-pot hydrothermal method.X-ray diffractometry,Raman scattering and scanning electron microscopy revealed that the crystal phase transformed from the monoclinic phase to the tetragonal phase,probably owing to the substitution of europium ions in the Bi3+positions.Significant changes in the physical-chemical characteristics of the material with the initial molar ratio of Eu to Bi were observed.Adding the europium causes alteration of the BiVO4 structure from a monoclinic scheelite(x<3)to a tetragonal zircon(x≥3)structure with a mixed-phase state between them.The photocatalytic activities of the prepared samples were evaluated by degrading methylene blue(MB)under visible light irradiation and the best performance was attained for the EBVO-5 material with a phase transition trend.The results of the photoluminescence spectroscopy demonstrated that the recombination of photogenerated charges was greatly depressed and the photocatalytic activity was improved by the substitution of Eu for Bi in BiVO4.Furthermore,the proposed mechanism of the enhanced photocatalytic activity was discussed.展开更多
In this paper,a novel ionic liquid-assisted solvothermal method to prepare Cl-doped bismuth oxycarbonate(Bi_(2)O_(2)CO_(3))is presented.The ionic liquid of[Hnmp]Cl not only enhances the solvothermal process to help th...In this paper,a novel ionic liquid-assisted solvothermal method to prepare Cl-doped bismuth oxycarbonate(Bi_(2)O_(2)CO_(3))is presented.The ionic liquid of[Hnmp]Cl not only enhances the solvothermal process to help the formation of Bi_(2)O_(2)CO_(3),but also provides chloride element as a dopant.XRD and XPS show that all three samples are Bi_(2)O_(2)CO_(3) with high purity.XPS,solid EPR,and TEM results prove that Cl is doped into the Bi_(2)O_(2)CO_(3) lattice and oxygen vacancies are generated.DRS results show that after Cl doping,the absorption of visible light by Bi_(2)O_(2)CO_(3) is enhanced.Surface photovoltage(SPV)and transient photocurrent tests show that as the doping amount of Cl increases,the separation efficiency of photogenerated electron-hole pairs over Bi_(2)O_(2)CO_(3) improves.The photocatalytic activity of Bi_(2)O_(2)CO_(3) is evaluated by the degradation of rhodamine B,which is increased after Cl doping.This work would broaden the application of ionic liquids in the solvothermal process and deepen the understanding of anionic ion doping in Bi_(2)O_(2)CO_(3).展开更多
基金financially supported by the State Key Laboratory of Clean Energy Utilization(Open Fund Project No.ZJUCEU2021001)Natural Science Foundation of Jiangsu Province(No.BK20221312).
文摘Electrochemical conversion of CO_(2)to CO is an economically feasible method for mitigating greenhouse gas emissions.Among various electrochemical approaches,solid oxide electrolysis cells(SOECs)show high potential for CO_(2)reduction reaction(CO_(2)-RR)due to their ability to operate at high temperatures,resulting in fast reaction kinetics and increased efficiency.Considering their main energy loss is still associated with the large overpotential at the fuel electrode,the development of the highly efficient and durable cathode for SOECs has been extensively searched after.Here,we propose an A-site doping strategy to enhance the properties of Sr_(2)Fe_(1.5)Mo_(0.5)O_(6−δ)(SFM),which improve its performance as a cathode in SOECs for CO_(2)-RR,demonstrating favorable activity and durability.The structural and physiochemical characterizations,together with DFT calculations,show that the partial replacement of Sr by Bi in the SFM double perovskite not only improves CO_(2) adsorption capability at the catalyst surface but also enhances oxygen ionic conduction inside the bulk oxide,resulting in enhanced CO_(2)electrocatalysis performance in SOECs.Specifically,a La_(0.8)Sr_(0.2)Ga_(0.8)Mg_(0.2)O_(3−δ) (LSGM)electrolyte-supported single cell with the new Bi-doped SFM cathode demonstrates a large current density of 1620 mA cm^(−2) at a cell potential of 1.6 V at 850°C with good operational stability up to 200 h.Bi-doped SFM thus represents a highly promising cathode for ceramic CO_(2)electrolyzers and could accelerate our transition towards a carbon-neutral society.
基金Supported by the National Natural Science Foundation of China (No.50672087 and No.60778039)National Basic Research Program of China (No.2006CB806000)+1 种基金National High Technology Program of China (No.2006AA03Z304)supported by Program for Changjiang Scholars and Innovative Research Team in University
文摘We report on broadband infrared emission of bismuth-doped RO-B2O3（R=Ca, Sr, Ba） glasses. Glass samples are prepared under various conditions by a conventional melting-quenching method and the luminescence properties in infrared wavelength region are investigated. No apparent infrared luminescence is observed in the SrO-B2O3 and BaO-B2O3 prepared in air, while glasses prepared in reducing atmosphere exhibit a broadband infrared luminescence peaking at 1 300 nm with a full width at half maximum（FWHM） of about 200 nm when excited by an 800 nm laser diode. A mechanism was proposed to explain the observed phenomena. The presence of low valence bismuth, probably Bi^＋, is responsible for the broadband infrared emission.
文摘Nd∶NBW laser crystal with the size of Φ8 mm×20 mm was grown by the process of lifting and pulling. The growth technological parameters which have influence on the completeness of crystal were analyzed and the reasonable technological parameters were ascertained.
基金financially supported by National Natural Science Foundation of China(51974168)Science and Technology Major Project Inner Mongolia Autonomous Region in China(2019ZD023 and 2021ZD0028)State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)(SYSJJ2020-08).
文摘Europium-doped bismuth vanadate EBVO-x(0≤x≤7)with different crystalline phases has been successfully synthesized via a simple one-pot hydrothermal method.X-ray diffractometry,Raman scattering and scanning electron microscopy revealed that the crystal phase transformed from the monoclinic phase to the tetragonal phase,probably owing to the substitution of europium ions in the Bi3+positions.Significant changes in the physical-chemical characteristics of the material with the initial molar ratio of Eu to Bi were observed.Adding the europium causes alteration of the BiVO4 structure from a monoclinic scheelite(x<3)to a tetragonal zircon(x≥3)structure with a mixed-phase state between them.The photocatalytic activities of the prepared samples were evaluated by degrading methylene blue(MB)under visible light irradiation and the best performance was attained for the EBVO-5 material with a phase transition trend.The results of the photoluminescence spectroscopy demonstrated that the recombination of photogenerated charges was greatly depressed and the photocatalytic activity was improved by the substitution of Eu for Bi in BiVO4.Furthermore,the proposed mechanism of the enhanced photocatalytic activity was discussed.
基金the National Natural Science Foundation of China(No.21776059 and 21376061)the Natural Science Foundation for Distinguished Young Scholar of Hebei Province(B2015208010)the Foundation for the Returned Overseas Chinese Scholars of Hebei Province(CL201609).
文摘In this paper,a novel ionic liquid-assisted solvothermal method to prepare Cl-doped bismuth oxycarbonate(Bi_(2)O_(2)CO_(3))is presented.The ionic liquid of[Hnmp]Cl not only enhances the solvothermal process to help the formation of Bi_(2)O_(2)CO_(3),but also provides chloride element as a dopant.XRD and XPS show that all three samples are Bi_(2)O_(2)CO_(3) with high purity.XPS,solid EPR,and TEM results prove that Cl is doped into the Bi_(2)O_(2)CO_(3) lattice and oxygen vacancies are generated.DRS results show that after Cl doping,the absorption of visible light by Bi_(2)O_(2)CO_(3) is enhanced.Surface photovoltage(SPV)and transient photocurrent tests show that as the doping amount of Cl increases,the separation efficiency of photogenerated electron-hole pairs over Bi_(2)O_(2)CO_(3) improves.The photocatalytic activity of Bi_(2)O_(2)CO_(3) is evaluated by the degradation of rhodamine B,which is increased after Cl doping.This work would broaden the application of ionic liquids in the solvothermal process and deepen the understanding of anionic ion doping in Bi_(2)O_(2)CO_(3).
