Porous nitrogen-doped carbon is an especially promising material energy storage due to its excellentconductivity, stable physicochemical properties, easy processability, controllable porosity and low price.Herein, we ...Porous nitrogen-doped carbon is an especially promising material energy storage due to its excellentconductivity, stable physicochemical properties, easy processability, controllable porosity and low price.Herein, we reported a novel well-designed hierarchically porous nitrogen-doped carbon （HPNC） via acombination of salt template （ZnC12） and hard template （SiO2） as sulfur host for lithium-sulfur batter-ies. The low-melting ZnC12 is boiled off and leaves behind micropores and small size mesopores duringpyrolysis process, while the silica spheres are removed by acid leaching to generate interconnected 3Dnetwork of macropores. The HPNC-S electrode exhibits an initial specific capacity of 1355 mAh g^-l at 0.IC （IC= 1675 mAh g^-1 ）, a high-rate capability of 623 mAh g-l at 2 C, and a small decay of 0.13% per cycleover 300 cycles at 0.2 C. This excellent rate capability and remarkable long-term cyclability of the HPNC-Selectrode are attributed to its hierarchical porous structures for confining the soluble lithium polysulfideas well as the nitrogen doping for high absorbability of lithium polysulfide.展开更多
Electrocatalytic conversion of oxygen holds great potential for clean energy technologies, including water electrolysis, regenerative fuel cells, and rechargeable metal-air batteries. The development of highly efficie...Electrocatalytic conversion of oxygen holds great potential for clean energy technologies, including water electrolysis, regenerative fuel cells, and rechargeable metal-air batteries. The development of highly efficient and inexpensive oxygen electrocatalysts as replacements for precious metal-based catalysts is vitally important for large-scale practical application in the future. A bifunctional oxygen electrocatalyst based on FeCo nanoparticles/N-doped carbon core-shell spheres supported on N-doped graphene sheets was prepared via one-step pyrolysis of graphitic carbon nitride and acetylacetonates. The optimized product exhibited an oxygen electrode activity of 0.87 V and excellent durability. The remarkable performance is mainly attributed to the synergetic effect arising from the FeCo nanoparticles and N-doped carbon shell. This study introduces an inexpensive and simple way to develop highly active bifunctional oxygen electrocatalysts.展开更多
A Co-based metal-organic framework （Co-MOF） with a unique three-dimensional starfish-like nanostructure was successfully synthesized using a simple ultrasonic method. After subsequent carbonization and oxidation, a ...A Co-based metal-organic framework （Co-MOF） with a unique three-dimensional starfish-like nanostructure was successfully synthesized using a simple ultrasonic method. After subsequent carbonization and oxidation, a nanocomposite of nitrogen-doped carbon with a Co3O4 coating （Co3O4@N-C） with a porous starfish-like nanostructure was obtained. The final hybrid exhibited excellent lithium storage performance when evaluated as an anode material in a lithiumion battery. A remarkable and stable discharge capacity of 795 mAh·g^-1 was maintained at 0.5 A·g^-1 after 300 cycles. Excellent rate capability was also obtained. In addition, a full Co3O4@N-C/LiFePO4 battery displayed stable capacity retention of 95% after 100 cycles. This excellent lithium storage performance is attributed to the unique porous starfish-like structure, which effectively buffers the volume expansion that occurs during Li^＋ insertion/deinsertion. Meanwhile, the nitrogendoped carbon coating enhances the electrical conductivity and provides a buffer layer to accommodate the volume change and accelerate the formation of a stable solid electrolyte interface layer.展开更多
Phosphate residue is regarded as a hazardous waste, which could potentially create significant environmental and health problems if it is not properly treated and disposed of. In this study, nitrogen-doped carbon nano...Phosphate residue is regarded as a hazardous waste, which could potentially create significant environmental and health problems if it is not properly treated and disposed of. In this study, nitrogen-doped carbon nanotubes-FePO_4(NCNTs-FePO_4) composite was successfully synthesized from phosphate residue, and its application as an effective catalyst was explored. Firstly, an effective method was developed to recover FePO_4 from phosphate residue, achieving an impressive FePO_4 mass recovery rate of 98.14%. Then, the NCNTsFePO_4 catalyst was synthesized from the recovered FePO_4 by two main reactions, including surface modification and chemical vapor deposition. Finally, the synthesized NCNTs-FePO_4 was applied to photo-degrade 15 mg/L Rhodamine B(RhB) in a Fenton-like system. The results showed that 98.9% of RhB could be degraded in 60 min, closely following the pseudofirst-order kinetics model. It was found that even after six consecutive cycles, NCNTs-FePO_4 still retained a high catalytic capacity(>50%). Moreover, ·OH radicals participating in the RhB degradation process were evidenced using quenching experiments and electron paramagnetic resonance analysis, and a rational mechanism was proposed. It was demonstrated that the materials synthesized from hazardous phosphate residue can be used as an effective catalyst for dye removal.展开更多
Herein, Co_3O_4 nanoparticles/nitrogen-doped carbon(Co_3O_4/NPC) composites with different structures were prepared via a facile method. Structure control was achieved by the rational morphology design of ZIF-67 precu...Herein, Co_3O_4 nanoparticles/nitrogen-doped carbon(Co_3O_4/NPC) composites with different structures were prepared via a facile method. Structure control was achieved by the rational morphology design of ZIF-67 precursors, which were then pyrolyzed in air to obtain Co_3O_4/NPC composites. When applied as catalysts for the oxygen evolution reaction(OER), the M-Co_3O_4/NPC composites derived from the flower-like ZIF-67 showedsuperior catalytic activities than those derived from the rhombic dodecahedron and hollow spherical ZIF-67. The former M-Co_3O_4/NPC composite displayed a small overpotential of 0.3 V, low onset potential of 1.41 V, small Tafel slope of 83 m V dec^(-1), and a desirable stability.(94.7% OER activity was retained after 10 h.) The excellent performance of the flower-like M-Co_3O_4/NPC composite in the OER was attributed to its favorable structure.展开更多
基金National Natural Science Foundation of China(51572172,51602332)Equipment Research Program(6140721050215)One-Hundred Talent Plan of Chinese Academy of Sciences
基金financially supported by the National Key Research and Development Program of China (2016YFB0101202)the NSFC of China (Grants 91534205,21436003 and 21576031)Graduate Research and Innovation Foundation of Chongqing China (Grant No.CYB17021)
文摘Porous nitrogen-doped carbon is an especially promising material energy storage due to its excellentconductivity, stable physicochemical properties, easy processability, controllable porosity and low price.Herein, we reported a novel well-designed hierarchically porous nitrogen-doped carbon （HPNC） via acombination of salt template （ZnC12） and hard template （SiO2） as sulfur host for lithium-sulfur batter-ies. The low-melting ZnC12 is boiled off and leaves behind micropores and small size mesopores duringpyrolysis process, while the silica spheres are removed by acid leaching to generate interconnected 3Dnetwork of macropores. The HPNC-S electrode exhibits an initial specific capacity of 1355 mAh g^-l at 0.IC （IC= 1675 mAh g^-1 ）, a high-rate capability of 623 mAh g-l at 2 C, and a small decay of 0.13% per cycleover 300 cycles at 0.2 C. This excellent rate capability and remarkable long-term cyclability of the HPNC-Selectrode are attributed to its hierarchical porous structures for confining the soluble lithium polysulfideas well as the nitrogen doping for high absorbability of lithium polysulfide.
基金The work was financially supported by the National Natural Science Foundation of China （No. 51173202）, Innovation Foundation for Superior Postgraduate of National University of Defense Technology, Hunan Provincial Innovation Foundation for Postgraduate, Research Project of NUDT （No. ZK16-03-32）, Aid Program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province and Aid Program for Innovative Group of National University of Defense Technology.
文摘Electrocatalytic conversion of oxygen holds great potential for clean energy technologies, including water electrolysis, regenerative fuel cells, and rechargeable metal-air batteries. The development of highly efficient and inexpensive oxygen electrocatalysts as replacements for precious metal-based catalysts is vitally important for large-scale practical application in the future. A bifunctional oxygen electrocatalyst based on FeCo nanoparticles/N-doped carbon core-shell spheres supported on N-doped graphene sheets was prepared via one-step pyrolysis of graphitic carbon nitride and acetylacetonates. The optimized product exhibited an oxygen electrode activity of 0.87 V and excellent durability. The remarkable performance is mainly attributed to the synergetic effect arising from the FeCo nanoparticles and N-doped carbon shell. This study introduces an inexpensive and simple way to develop highly active bifunctional oxygen electrocatalysts.
基金Acknowledgements This work is supported by the National Natural Science Foundation of China （Nos. 21173001 and 21371003） and Anhui Province Key Laboratory of Environment-Friendly Polymer Materials.
文摘A Co-based metal-organic framework （Co-MOF） with a unique three-dimensional starfish-like nanostructure was successfully synthesized using a simple ultrasonic method. After subsequent carbonization and oxidation, a nanocomposite of nitrogen-doped carbon with a Co3O4 coating （Co3O4@N-C） with a porous starfish-like nanostructure was obtained. The final hybrid exhibited excellent lithium storage performance when evaluated as an anode material in a lithiumion battery. A remarkable and stable discharge capacity of 795 mAh·g^-1 was maintained at 0.5 A·g^-1 after 300 cycles. Excellent rate capability was also obtained. In addition, a full Co3O4@N-C/LiFePO4 battery displayed stable capacity retention of 95% after 100 cycles. This excellent lithium storage performance is attributed to the unique porous starfish-like structure, which effectively buffers the volume expansion that occurs during Li^＋ insertion/deinsertion. Meanwhile, the nitrogendoped carbon coating enhances the electrical conductivity and provides a buffer layer to accommodate the volume change and accelerate the formation of a stable solid electrolyte interface layer.
基金supported by the Science and Technology Development Foundation of Pudong New Area (No.PKJ2014Z03)Dawn Program of Shanghai (No.09SG54)+1 种基金Material Science and Engineering Key Subject of Shanghai Polytechnic University (No.XXKZD1601)Gaoyuan Discipline of Shanghai-Environmental Science and Engineering (Resource Recycling Science and Engineering)
文摘Phosphate residue is regarded as a hazardous waste, which could potentially create significant environmental and health problems if it is not properly treated and disposed of. In this study, nitrogen-doped carbon nanotubes-FePO_4(NCNTs-FePO_4) composite was successfully synthesized from phosphate residue, and its application as an effective catalyst was explored. Firstly, an effective method was developed to recover FePO_4 from phosphate residue, achieving an impressive FePO_4 mass recovery rate of 98.14%. Then, the NCNTsFePO_4 catalyst was synthesized from the recovered FePO_4 by two main reactions, including surface modification and chemical vapor deposition. Finally, the synthesized NCNTs-FePO_4 was applied to photo-degrade 15 mg/L Rhodamine B(RhB) in a Fenton-like system. The results showed that 98.9% of RhB could be degraded in 60 min, closely following the pseudofirst-order kinetics model. It was found that even after six consecutive cycles, NCNTs-FePO_4 still retained a high catalytic capacity(>50%). Moreover, ·OH radicals participating in the RhB degradation process were evidenced using quenching experiments and electron paramagnetic resonance analysis, and a rational mechanism was proposed. It was demonstrated that the materials synthesized from hazardous phosphate residue can be used as an effective catalyst for dye removal.
基金supported by the Scientific and Technological Innovation Platform of Fujian Province(2006L2003)Scientific Research Project of Wuyi University(YJ201706)
文摘Herein, Co_3O_4 nanoparticles/nitrogen-doped carbon(Co_3O_4/NPC) composites with different structures were prepared via a facile method. Structure control was achieved by the rational morphology design of ZIF-67 precursors, which were then pyrolyzed in air to obtain Co_3O_4/NPC composites. When applied as catalysts for the oxygen evolution reaction(OER), the M-Co_3O_4/NPC composites derived from the flower-like ZIF-67 showedsuperior catalytic activities than those derived from the rhombic dodecahedron and hollow spherical ZIF-67. The former M-Co_3O_4/NPC composite displayed a small overpotential of 0.3 V, low onset potential of 1.41 V, small Tafel slope of 83 m V dec^(-1), and a desirable stability.(94.7% OER activity was retained after 10 h.) The excellent performance of the flower-like M-Co_3O_4/NPC composite in the OER was attributed to its favorable structure.
基金supported by the National Natural Science Foundation of China(No.51772133)the Taishan Scholar Project of Shandong Province,China(ZR2017JL022)+1 种基金the Project of“20 Items of University”of Jinan,China(No.2018GXRC001)Case-by-Case Project for Top Outstanding Talents of Jinan,China。
