In situ formed oxy/hydroxide antennas accelerating the water dissociation kinetics on a Co@N-doped carbon core-shell assembly for hydrogen production in alkaline solution

Tao Yang; Lang Pei; Shicheng Yan; Zhentao Yu; Tao Yu; Zhigang Zou

doi:10.1039/c9dt02301a

In situ formed oxy/hydroxide antennas accelerating the water dissociation kinetics on a Co@N-doped carbon core-shell assembly for hydrogen production in alkaline solution

Dalton Trans. 2019 Aug 21;48(31):11927-11933. doi: 10.1039/c9dt02301a. Epub 2019 Jul 18.

Authors

Tao Yang¹, Lang Pei², Shicheng Yan¹, Zhentao Yu¹, Tao Yu³, Zhigang Zou⁴

Affiliations

¹ Jiangsu Key Laboratory of Artificial Functional Materials, National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu 210093, P. R. China. yscfei@nju.edu.cn.
² College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou, Zhejiang 310018, P.R. China.
³ Jiangsu Province Key Laboratory for Nanotechnology, School of Physics, Nanjing University, Nanjing, Jiangsu 210093, P. R. China.
⁴ Jiangsu Key Laboratory of Artificial Functional Materials, National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, Nanjing University, Nanjing, Jiangsu 210093, P. R. China. yscfei@nju.edu.cn and Jiangsu Province Key Laboratory for Nanotechnology, School of Physics, Nanjing University, Nanjing, Jiangsu 210093, P. R. China.

PMID: 31317159
DOI: 10.1039/c9dt02301a

Abstract

The hydrogen evolution reaction (HER) in alkaline electrolytes is restricted severely by sluggish water dissociation in the Volmer step. Here, we embedded Co crystals into a N-doped carbon (Co@NC) on nickel foam (NF) framework and electrochemically oxidized them in situ to construct a CoO_xH_y [a mixture of Co(OH)₂ and CoOOH] antenna-modified Co@NC core-shell assembly (NF/Co@NC/CoO_xH_y). The CoO_xH_y antennas significantly decreased the activation energy of water dissociation to protons (the Volmer step), and hydrogen production over the Co core activated NC shell may follow a multi-carbon catalytic mechanism activated by Co and N atoms. As a result, the NF/Co@NC/CoO_xH_y configuration exhibits a 40 mV onset potential, a low HER overpotential of 51 mV at 10 mA cm^-2, and a current density still reaching around 20 mA cm^-2 after 55 h of stability testing in alkaline electrolyte. Our material functionalization strategy may open up a new approach for developing water-alkali electrolysers for use in efficient renewable energy conversion.