The experimental arrangement in this investigation was one in which a poly(o-aminophenol) (POAP) film was supported on a thin gold film electrode whose thickness is of the order of the mean free path of conduction ele...The experimental arrangement in this investigation was one in which a poly(o-aminophenol) (POAP) film was supported on a thin gold film electrode whose thickness is of the order of the mean free path of conduction electrons of gold. This arrangement allows one to apply the surface resistance technique to study the electrochemical processes occurring at the metal film surface coated with the polymer film. The dependence of the resistance change of the thin gold film electrode on the external electrolyte composition for polymer thickness lower than 0.25 mC.cm-2, was attributed to a competition, at the gold film surface, between the redox process of the polymer and adsorption of different ion species contained in the electrolyte. This competition reflects a discontinuous character of polymer thickness lower than 0.25 mC.cm-2 at the metal polymer interface. The resistance response of the metal film becomes independent of both the external electrolyte composition and polymer thickness for polymer thickness higher than 0.8 mC.cm-2. Then, POAP thicknesses higher than 0.8 mC.cm-2 seem to be compact enough at the metal polymer interface to prevent the interaction of the species contained in the supporting electrolyte with the gold film surface. The increase of the gold film resistance in going from the reduced to the oxidized state for POAP thicknesses higher than 0.8 mC.cm-2 was attributed to the redox conversion of poly(o-aminophenol) from amine to imine groups. This resistance increase was explained as a transition from specular to diffuse scattering of conduction electrons of gold at the gold poly(o-aminophenol) interface due to a less compact distribution of oxidised sites of POAP as compared with that of the reduced ones. An attenuation of the resistance response of the gold film was observed when the POAP films were deactivated either by contact with a ferric cation solution or prolonged potential cycling. The deactivation of the polymer film was attributed to the creation of inactive gaps within the redox sites configuration of POAP. The surface resistance technique allows one to detect different redox sites configurations of POAP on the gold film, according to the method used to deactivate the polymer films. In this work, it is demonstrated that the surface resistance technique can be employed to study not only the ability of a POAP film to inhibit the interaction of different species in solution with a metal surface but also the deactivation of the polymer film.展开更多
研发长效稳定、pH适应性强的析氢反应(HER)催化剂对实现大规模制氢具有重要意义.界面工程是研发高效HER催化剂的有效策略之一.本文成功构建了海胆状异质结构催化剂CoTe-CoP/NF.CoTe和CoP的协同作用不仅优化了电子结构、暴露了更多的活...研发长效稳定、pH适应性强的析氢反应(HER)催化剂对实现大规模制氢具有重要意义.界面工程是研发高效HER催化剂的有效策略之一.本文成功构建了海胆状异质结构催化剂CoTe-CoP/NF.CoTe和CoP的协同作用不仅优化了电子结构、暴露了更多的活性位点,而且有效地提高了催化剂的亲水性和疏气性.密度泛函理论计算表明:CoTe与CoP之间的相互作用有效地降低了水的解离能垒,同时增强了对H~*的吸附.这些结果使得CoTe-CoP/NF在整个pH范围内具有优异的HER性能和催化稳定性.在酸性、碱性和中性介质中,CoTe-CoP/NF电极驱动10 mA cm^(-2)的电流密度仅需51、53和75 mV的过电位.总之,本工作为在全pH范围内构建高性能HER催化剂提供了一种界面工程新策略.展开更多
文摘The experimental arrangement in this investigation was one in which a poly(o-aminophenol) (POAP) film was supported on a thin gold film electrode whose thickness is of the order of the mean free path of conduction electrons of gold. This arrangement allows one to apply the surface resistance technique to study the electrochemical processes occurring at the metal film surface coated with the polymer film. The dependence of the resistance change of the thin gold film electrode on the external electrolyte composition for polymer thickness lower than 0.25 mC.cm-2, was attributed to a competition, at the gold film surface, between the redox process of the polymer and adsorption of different ion species contained in the electrolyte. This competition reflects a discontinuous character of polymer thickness lower than 0.25 mC.cm-2 at the metal polymer interface. The resistance response of the metal film becomes independent of both the external electrolyte composition and polymer thickness for polymer thickness higher than 0.8 mC.cm-2. Then, POAP thicknesses higher than 0.8 mC.cm-2 seem to be compact enough at the metal polymer interface to prevent the interaction of the species contained in the supporting electrolyte with the gold film surface. The increase of the gold film resistance in going from the reduced to the oxidized state for POAP thicknesses higher than 0.8 mC.cm-2 was attributed to the redox conversion of poly(o-aminophenol) from amine to imine groups. This resistance increase was explained as a transition from specular to diffuse scattering of conduction electrons of gold at the gold poly(o-aminophenol) interface due to a less compact distribution of oxidised sites of POAP as compared with that of the reduced ones. An attenuation of the resistance response of the gold film was observed when the POAP films were deactivated either by contact with a ferric cation solution or prolonged potential cycling. The deactivation of the polymer film was attributed to the creation of inactive gaps within the redox sites configuration of POAP. The surface resistance technique allows one to detect different redox sites configurations of POAP on the gold film, according to the method used to deactivate the polymer films. In this work, it is demonstrated that the surface resistance technique can be employed to study not only the ability of a POAP film to inhibit the interaction of different species in solution with a metal surface but also the deactivation of the polymer film.
基金supported by Outstanding Talent Fund from Beijing University of Chemical Technology。
文摘研发长效稳定、pH适应性强的析氢反应(HER)催化剂对实现大规模制氢具有重要意义.界面工程是研发高效HER催化剂的有效策略之一.本文成功构建了海胆状异质结构催化剂CoTe-CoP/NF.CoTe和CoP的协同作用不仅优化了电子结构、暴露了更多的活性位点,而且有效地提高了催化剂的亲水性和疏气性.密度泛函理论计算表明:CoTe与CoP之间的相互作用有效地降低了水的解离能垒,同时增强了对H~*的吸附.这些结果使得CoTe-CoP/NF在整个pH范围内具有优异的HER性能和催化稳定性.在酸性、碱性和中性介质中,CoTe-CoP/NF电极驱动10 mA cm^(-2)的电流密度仅需51、53和75 mV的过电位.总之,本工作为在全pH范围内构建高性能HER催化剂提供了一种界面工程新策略.
基金supported by the National Natural Science Foundation of China(52172156,51832005)the Natural Science Foundation of Fujian Province of China(2023J06005)the Natural Science Foundation of Zhejiang Province(LD22E010001)。
