Activating Inert Sites in Cobalt Silicate Hydroxides for Oxygen Evolution through Atomically Doping

Energy & Environmental Materials

article

Jiexin Zhu¹  Lixue Xia²  Wenxuan Yang¹  Ruohan Yu¹  Wei Zhang¹  Wen Luo¹  Yuhang Dai¹  Wei Wei¹  Liang Zhou¹  Yan Zhao²  Liqiang Mai¹ 

[1] State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology;International School of Materials Science and Engineering, Wuhan University of Technology;Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory

关键词: atomically doping;    electrochemistry;    electron transfer;    metal silicate hydroxides;    oxygen evolution;   

DOI  :  10.1002/eem2.12219

来源: Wiley

【 摘 要 】

Metal silicate hydroxides have been recognized as efficient oxygen evolution reaction (OER) electrocatalysts, yet tailoring of their intrinsic activity remains confused. Herein, Fe had been incorporated into cobalt silicate hydroxide nanosheets and the resulted material achieves a competitive OER catalytic activity. It is found that the doping state obviously affects the electrical transport property. Specifically, highly dispersed Fe atoms (low-concentration Fe doping) trigger slight electron transfer to Co atoms while serried Fe (high-concentration Fe doping) attract vast electrons. By introducing 6 at.% Fe doping, partial relatively inert Co sites are activated by atomically dispersed Fe, bearing an optimal metal 3 d electronic occupation and adsorption capacity to oxygen intermediate. The introduced Co−O−Fe unit trigger the π -donation effect and decrease the number of electrons in π *-antibonding orbitals, which enhance the Fe−O covalency and the structural stability. As a result, the sample delivers a low overpotential of 293 mV to achieve a current density of 10 mA cm −2 . This work clarifies the superiority of atomically dispersed doping state, which is of fundamental interest to the design of doped catalyst.

【 授权许可】

Unknown