Activated overall water splitting over a Ni-Fe layered double hydroxide electrocatalyst by V doping and sulfuration

• Published in: Applications in energy and combustion science Vol. 14; p. 100148
• Main Authors: Wu, Wentong, Peng, Lei, Min, Boya, Huang, Jie, Liu, Saiya, Lu, Kejian, Lu, Shijian, Jing, Dengwei, Zheng, Mingsheng, Liu, Maochang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2023; Elsevier
• Subjects: NiFe-LDH; Non-noble electrocatalyst; Sulfuration; Ternary transition metal sulfide; V doping; Sulfuration; Ternary transition metal sulfide; Non-noble electrocatalyst; V doping; NiFe-LDH
• ISSN: 2666-352X; 2666-352X
• DOI: 10.1016/j.jaecs.2023.100148

•A Ni-foam supported NiFe-LDH composite is modified by V doping and vulcanization.•The modified composite can serve as both the cathode and anode for water splitting.•Superior bifunctional electrocatalytic water splitting could be achieved.•A cell voltage of 1.573 V at 10 mA cm−2 can be gained for stable water splitting.•The superiority relies on improved conductivity and increased active sites. Ni-Fe layered double hydroxide (NiFe-LDH) is regarded as one of the promising non-noble electrocatalyst. However, the limited number of active sites and poor electrical conductivity impede its further development. Herein, we report the synthesis of a Ni foam supported NiFe-LDH electrocatalyst modified by V doping and sulfuration (NiFeV-S/NF). This modification endows the catalyst excellent property toward hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and overall water splitting. Only 211 mV and 127 mV of the overpotentials are required to achieve the current density of 10 mA cm−2 for OER and HER in 1 M KOH electrolyte, respectively. Particularly, the prepared NiFeV-S/NF could serve as a bifunctional electrocatalyst for overall water splitting, with a cell voltage of 1.573 V to reach a current density of 10 mA cm−2. In principle, the success relies on the intrinsically improved conductivity, increased specific surface area and the number of active sites, as well as the heterojunction structure of the catalyst. Therefore, this work provides a new idea for the design and preparation of more efficient noble-metal-free bifunctional electrocatalysts.