Sulfur doping and heterostructure on NiSe@Co(OH)2 with facilitated surface reconstruction and interfacial electron regulation to boost oxygen evolution reaction

• Published in: Fuel (Guildford) 2025-03, Vol.384, Article 133978
• Main Authors: Nie, Fei, Wen, Jinghong, Chong, Xiaodan, Dai, Xiaoping, Yang, Yikai, zhao, JinSheng
• Format: Article
• Language: English
• Subjects: Interfacial electron regulation; NiSe@S-CoOOH; Oxygen evolution reaction; Sulfur doping; Surface reconstruction
• ISSN: 0016-2361
• DOI: 10.1016/j.fuel.2024.133978

•Three-dimensional NiSe@S-Co(OH)2 nanoarrays were constructed by hydrothermal and electrodeposition processes.•S doping facilitated the surface redistribution of Co(OH)2 to active sites CoOOH.•S doping and NiSe@S-CoOOH heterostructure - optimize- reaction pathway and reduce - energy barrier of the rate-limiting steps.•NiSe@S-Co(OH)2 nanoarrays exhibits excellent OER performance and robust stability. Cobalt hydroxide (Co(OH)2) with nanosheets structure are considered as promising OER electrocatalysts due to the divalent cobalt ions occupied octahedral (MO6) structure and the exposition of more active sites, but pure Co(OH)2 suffers from poor OER performance because of the sluggish OER kinetics and poor mass-transport ability. Herein, three-dimensional NiSe@S-Co(OH)2 nanoarrays are synthesized by electrodepositing S doped Co(OH)2 nanosheets on NiSe nanowires/Ni foam. The optimal NiSe@S-Co(OH)2 achieves lower overpotential (285 mV at 50 mA cm−2) with smaller Tafel slope (101.8 mV dec-1) in basic solution. In-situ UV–vis experiments unveil that S doping can facilitate the formation of CoOOH (active sites) reconstructed from Co(OH)2. The experiments and theoretical simulations prove that the intense electronic interaction exists at the interface of NiSe@S-CoOOH, where the electrons transfer from NiSe to S-CoOOH. The interfacial synergy induced by coupling NiSe and sulfur doping can change the rate-controlling step and reduce the energy barrier from 3.17 eV (S-CoOOH) and 2.59 eV (NiSe@CoOOH) to 1.93 eV (NiSe@S-CoOOH). The two-electrode electrolyer made up of NiSe@S-Co(OH)2//Pt-C couple reveal the low potential of 1.78 V at 300 mA cm−2 for all alkaline water splitting. This work puts forward a simple tactic for synthesizing three-dimensional structure, and combines interfacial electron regulation and active sites engineering to enhance OER activities of Co(OH)2.