Enhanced water electrolysis activity by CoNi-LDH/Co -nitrogen-doped carbon heterostructure with dual catalytic active sites. (10th March 2023)

• Record Type: Journal Article
• Authors: Sang, Yan; Guo, Zixuan; Li, Guohong; Xue, Yingying; Xue, Jingwei
• Is Part Of: Electrochimica acta. Volume 444(2023)
• Publication Date: 2023-03-10
• Subjects: Water splitting -- Electrochemistry -- Cooperative effects -- Metal-organic frameworks -- Layered double hydroxides; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2023.141956
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: The CoNi-LDH/Co@NC was constructed by calcination and solvothermal method. The CoNi-LDH/Co@NC accelerates the charge transfer. The CoNi-LDH/Co@NC catalyst exhibits remarkable catalytic activity for water splitting. The CoNi-LDH/Co@NC exhibits an overpotential of 75 mV for HER and 207 mV for OER at 10 mA cm −2 . Abstract: The study and development of bifunctional non-precious metal catalysts with excellent oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) electrocatalytic activities are particularly important and challenging for electrocatalytic total water splitting. Here, we report a non-precious material constructed by growing cobalt-nickel double hydroxides on ZIF-derived Co nanoparticles and nitrogen-doped carbon framework (CoNi-LDH/Co@NC), which exhibits excellent electrocatalytic performances for both OER and HER in alkaline media. When used as OER and HER electrocatalysts, CoNi-LDH/Co@NC only needs 359 mV and 187 mV overpotentials at a current density of 100 mA cm −2, respectively. Surprisingly, using CoNi-LDH/Co@NC as both cathode and anode for a two-electrode water splitting system, a small battery voltage of 1.51 V is required at the current density of 10 mA cm −2, and the current density remained stable for 20 h without any obvious attenuation. This opens up new possibilities for further exploration of non-precious metal electrocatalysts for water splitting. Graphical abstract: CoNi-LDH/Co@NC materials retaining the original ZIF-67 configuration were successfully synthesized by a facile calcination assisted solvothermal methods. Due to the synergistic effect of CoNi-LDH and Co@NC, the N-doping, high electrical conductivity and the large specific surface area of NC, the as-obtained CoNi-LDH/Co@NC can be used as an efficient and stable dual-function electrocatalyst to achieve efficient all-water splitting. Image, graphical abstract