Renewable lignin used for synthesizing materials has been proven to be highly potential in specific electrochemistry.Here,we report a simple method to synthesize nitrogen and sulfur co-doped carbon nanosheets by using...Renewable lignin used for synthesizing materials has been proven to be highly potential in specific electrochemistry.Here,we report a simple method to synthesize nitrogen and sulfur co-doped carbon nanosheets by using bagasse lignin,denoted as lignin-derived carbon(LC).By adjusting the ratio of nitrogen source and annealing temperature,we obtained the ultrathin graphitic lignin carbon(LC-4-1000)with abundant wrinkles with high surface area of 1208 m2g_1 and large pore volume of 1.40 cm3g_1.In alkaline medium,LC-4-1000 has more positive half-wave potential and nearly current density compared to commercial Pt/C for oxygen reduction reaction(ORR).More importantly,LC-4-1000 also exhibits comparable activity and superior stability for ORR in acid medium due to its high graphitic N ratio and a direct four electron pathway for ORR.This study develops a cost-effective and highly efficient method to prepare biocarbon catalyst for ORR in fuel cells.展开更多
Nitrogen and sulfur co-doped porous nanocarbon (ZIF-C-N-S) catalyst was successfully synthesized derived from ZIF-8 and thiourea precursors.The electrochemical measurements indicate that the as-obtained ZIF-C-N-S cata...Nitrogen and sulfur co-doped porous nanocarbon (ZIF-C-N-S) catalyst was successfully synthesized derived from ZIF-8 and thiourea precursors.The electrochemical measurements indicate that the as-obtained ZIF-C-N-S catalyst exhibits higher electrocatalytic activity for oxygen reduction reaction (ORR) in alkaline electrolyte and superior durability-longer than commercial Pt/C catalyst.The enhancment of electrocatalytic activity mainly be come from the open pore structure,large specific surface area as well as the synergistic effect resulted from the co-doping of N and S atoms.In addition,the ZIF-C-N-S catalyst is also used as the air cathode catalyst in the microbial fuel cell (MFC) device.The maximum power density and stable output voltage of ZIF-C-N-S based MFC are 1315 mW/m2 and 0.48 V,respectively,which is better than that of Pt/C based MFC.展开更多
Development of efficient and promising bifunctional electrocatalysts for oxygen reduction and evolutionreactions is desirable. Herein, cobalt nanoparticles embedded in nitrogen and sulfur co-doped carbonnanotubes(Co@N...Development of efficient and promising bifunctional electrocatalysts for oxygen reduction and evolutionreactions is desirable. Herein, cobalt nanoparticles embedded in nitrogen and sulfur co-doped carbonnanotubes(Co@NSCNT) were prepared by a facile pyrolytic treatment. The cobalt nanoparticles and co-doping of nitrogen and sulfur can improve the electron donor-acceptor characteristics of the carbon nan-otubes and provide more active sites for catalytic oxygen reduction and evolution reactions. The preparedCo@NSCNT, annealed at 900℃, showed excellent electrocatalytic performance and better durability thancommercial platinum catalysts. Additionally, Co@NSCNT-900 catalysts exhibited comparable onset poten-tials and Tafel slopes to ruthenium oxide. Overall, Co@NSCNT showed high activity and improved dura-bility for both oxygen evolution and reduction reactions.展开更多
A novel composite photocatalyst for photocatalytic decomposition of water for hydrogen evolution was successfully synthesized by in-situ growth of nitrogen and sulfur co-doped coal-based carbon quantum dots(NSCQDs)nan...A novel composite photocatalyst for photocatalytic decomposition of water for hydrogen evolution was successfully synthesized by in-situ growth of nitrogen and sulfur co-doped coal-based carbon quantum dots(NSCQDs)nanoparticles on the surface of sheet cobalt-based metal-organic framework(Co-MOF)and graphitic carbon nitride(g-C_(3)N_(4),CN).The structure and properties of the obtained catalysts were systematically analyzed.NSCQDs effectively broaden the absorption of Co-MOF and CN in the visible region.The new composite photocatalyst has high hydrogen production activity and the hydrogen production rate reaches 6254μmol/(g·h)at pH=9.At the same time,NSCQDs synergy Co-MOF/CN composites have good stability.After four cycles of hydrogen production,the performance remains relatively stable.The tran sient photocurrent response and Nyquist plot experimental results further demonstrate the improvement of carrier separation efficiency in composite catalysts.The semiconductor type(n-type semico nductor)of the single-phase catalyst was determined by the Mott-Schottky test,and the band structure was analyzed.The conductive and valence bands of CN are-0.99 and 1.72 eV,respectively,and the conduction and valence bands of Co-MOF are-1.85 and 1.33 eV,respectively.Th e mechanism of the photocatalytic reaction can be inferred,that is,Z-type heterojunction is formed between CN an d Co-MOF,and NSCQDs was used as cocatalyst.展开更多
基金financial support from the National Natural Science Foundation of China (Nos. 21476089, 21373091)the Provincial Science and Technology Project of Guangdong (No. 2014A030312007)
文摘Renewable lignin used for synthesizing materials has been proven to be highly potential in specific electrochemistry.Here,we report a simple method to synthesize nitrogen and sulfur co-doped carbon nanosheets by using bagasse lignin,denoted as lignin-derived carbon(LC).By adjusting the ratio of nitrogen source and annealing temperature,we obtained the ultrathin graphitic lignin carbon(LC-4-1000)with abundant wrinkles with high surface area of 1208 m2g_1 and large pore volume of 1.40 cm3g_1.In alkaline medium,LC-4-1000 has more positive half-wave potential and nearly current density compared to commercial Pt/C for oxygen reduction reaction(ORR).More importantly,LC-4-1000 also exhibits comparable activity and superior stability for ORR in acid medium due to its high graphitic N ratio and a direct four electron pathway for ORR.This study develops a cost-effective and highly efficient method to prepare biocarbon catalyst for ORR in fuel cells.
基金the National Natural Science Foundation of China(No.51472034)the Opening Project of Key Laboratory of Optoelectronic Chemical Materials and Devices,Ministry of Education,Jianghan University(No.JDGD-201806)。
文摘Nitrogen and sulfur co-doped porous nanocarbon (ZIF-C-N-S) catalyst was successfully synthesized derived from ZIF-8 and thiourea precursors.The electrochemical measurements indicate that the as-obtained ZIF-C-N-S catalyst exhibits higher electrocatalytic activity for oxygen reduction reaction (ORR) in alkaline electrolyte and superior durability-longer than commercial Pt/C catalyst.The enhancment of electrocatalytic activity mainly be come from the open pore structure,large specific surface area as well as the synergistic effect resulted from the co-doping of N and S atoms.In addition,the ZIF-C-N-S catalyst is also used as the air cathode catalyst in the microbial fuel cell (MFC) device.The maximum power density and stable output voltage of ZIF-C-N-S based MFC are 1315 mW/m2 and 0.48 V,respectively,which is better than that of Pt/C based MFC.
基金supported by the Human Resources Development(No.20184030202070) of the Korea Institute of Energy Technology Evaluation and Planning(KETEP) grant funded by the Korea government Ministry of Trade, Industry and Energy
文摘Development of efficient and promising bifunctional electrocatalysts for oxygen reduction and evolutionreactions is desirable. Herein, cobalt nanoparticles embedded in nitrogen and sulfur co-doped carbonnanotubes(Co@NSCNT) were prepared by a facile pyrolytic treatment. The cobalt nanoparticles and co-doping of nitrogen and sulfur can improve the electron donor-acceptor characteristics of the carbon nan-otubes and provide more active sites for catalytic oxygen reduction and evolution reactions. The preparedCo@NSCNT, annealed at 900℃, showed excellent electrocatalytic performance and better durability thancommercial platinum catalysts. Additionally, Co@NSCNT-900 catalysts exhibited comparable onset poten-tials and Tafel slopes to ruthenium oxide. Overall, Co@NSCNT showed high activity and improved dura-bility for both oxygen evolution and reduction reactions.
基金Project supported by the Ningxia Natural Science Foundation of China(2023AAC03285)National Natural Science Foundation of China(21666001)+1 种基金Innovative Team for Transforming Waste Cooking Oil into Clean Energy and High Value-added Chemicals,ChinaNingxia Low-grade Resource High Value Utilization and Environmental Chemical Integration Technology Innovation Team Project,China。
文摘A novel composite photocatalyst for photocatalytic decomposition of water for hydrogen evolution was successfully synthesized by in-situ growth of nitrogen and sulfur co-doped coal-based carbon quantum dots(NSCQDs)nanoparticles on the surface of sheet cobalt-based metal-organic framework(Co-MOF)and graphitic carbon nitride(g-C_(3)N_(4),CN).The structure and properties of the obtained catalysts were systematically analyzed.NSCQDs effectively broaden the absorption of Co-MOF and CN in the visible region.The new composite photocatalyst has high hydrogen production activity and the hydrogen production rate reaches 6254μmol/(g·h)at pH=9.At the same time,NSCQDs synergy Co-MOF/CN composites have good stability.After four cycles of hydrogen production,the performance remains relatively stable.The tran sient photocurrent response and Nyquist plot experimental results further demonstrate the improvement of carrier separation efficiency in composite catalysts.The semiconductor type(n-type semico nductor)of the single-phase catalyst was determined by the Mott-Schottky test,and the band structure was analyzed.The conductive and valence bands of CN are-0.99 and 1.72 eV,respectively,and the conduction and valence bands of Co-MOF are-1.85 and 1.33 eV,respectively.Th e mechanism of the photocatalytic reaction can be inferred,that is,Z-type heterojunction is formed between CN an d Co-MOF,and NSCQDs was used as cocatalyst.
