Catalysts consisting of Zeolite imidazolyl ester skeleton-67(ZIF-67)and graphene oxide(GO)were fabricated through a solvothermal method,followed by etching ZIF-67 with oxygen-rich functional groups on GO in a reductio...Catalysts consisting of Zeolite imidazolyl ester skeleton-67(ZIF-67)and graphene oxide(GO)were fabricated through a solvothermal method,followed by etching ZIF-67 with oxygen-rich functional groups on GO in a reduction atmosphere at 400℃.During this process,an open type of cobalt metal center was formed by the partial vaporization and oxidation of ZIF-67,further reducing to Co and partially combining with oxygen species to amorphous CoOx.Benefiting from the rich functional N,and metal/oxides active centers derived from the calcination process,the synthesized Co/CoOx@NSG-400 showed a low OER overpotential of 10 mA·cm^(-2) at 298 mV,and an ORR half-wave potential of 0.8 V,which demonstrated its excellent bifunctional catalytic activity.Such a controllable calcination strategy with high yields could be expected to pave the way for synthesizing low-cost and efficient bifunctional electrocatalysts.展开更多
Aiming to find suitable electrolytes for electric double layer capacitor (EDLC),the relationship between the formation velocity of electric double layer and the specific capacitance in different electrolyte (H 2 SO 4,...Aiming to find suitable electrolytes for electric double layer capacitor (EDLC),the relationship between the formation velocity of electric double layer and the specific capacitance in different electrolyte (H 2 SO 4,KOH,KCl,NH 4 Cl,and LiOH) solutions was investigated by cyclic voltammetry and AC impedance with varying frequency and potential,which was also analyzed based on Stern model and Gouy-Chapman diffusion layer model.It shows that the capacitance is positively correlated with the formation velocity of the electric double layers,which is affected by the type of ions applied,the concentration of the electrolyte solution,and the potential and frequencies as well.The electrolyte solutions of 6 mol/L KOH and 4 mol/L H 2 SO 4 provide the largest capacitance,reaching 214 and 186 μF/cm 2,respectively.Both 6 mol/L KOH and 4 mol/L H 2 SO 4 solutions are suitable electrolytes for EDLC applications using Pt as electrodes.展开更多
基金Funded in part by the National Natural Science Foundation of China(No.22279096)the Guangdong Basic and Applied Basic Research Foundation(No.2021B1515120072)the Guangdong Key R&D Program(No.2020B0909040001)。
文摘Catalysts consisting of Zeolite imidazolyl ester skeleton-67(ZIF-67)and graphene oxide(GO)were fabricated through a solvothermal method,followed by etching ZIF-67 with oxygen-rich functional groups on GO in a reduction atmosphere at 400℃.During this process,an open type of cobalt metal center was formed by the partial vaporization and oxidation of ZIF-67,further reducing to Co and partially combining with oxygen species to amorphous CoOx.Benefiting from the rich functional N,and metal/oxides active centers derived from the calcination process,the synthesized Co/CoOx@NSG-400 showed a low OER overpotential of 10 mA·cm^(-2) at 298 mV,and an ORR half-wave potential of 0.8 V,which demonstrated its excellent bifunctional catalytic activity.Such a controllable calcination strategy with high yields could be expected to pave the way for synthesizing low-cost and efficient bifunctional electrocatalysts.
基金Supported by the National Science and Technology Pillar Plan Project of China (2008BAE60B08)Science and Technology Project of Liaoning Province (2009304007)
文摘Aiming to find suitable electrolytes for electric double layer capacitor (EDLC),the relationship between the formation velocity of electric double layer and the specific capacitance in different electrolyte (H 2 SO 4,KOH,KCl,NH 4 Cl,and LiOH) solutions was investigated by cyclic voltammetry and AC impedance with varying frequency and potential,which was also analyzed based on Stern model and Gouy-Chapman diffusion layer model.It shows that the capacitance is positively correlated with the formation velocity of the electric double layers,which is affected by the type of ions applied,the concentration of the electrolyte solution,and the potential and frequencies as well.The electrolyte solutions of 6 mol/L KOH and 4 mol/L H 2 SO 4 provide the largest capacitance,reaching 214 and 186 μF/cm 2,respectively.Both 6 mol/L KOH and 4 mol/L H 2 SO 4 solutions are suitable electrolytes for EDLC applications using Pt as electrodes.
