Dual-Anion Doping Enables NiSe<sub>2</sub> Electrocatalysts to Accelerate Alkaline Hydrogen Evolution Reaction
Wenhao Yuan, Ying Li, Limin Liang, Fangqing Wang, Hui Liu
Abstract
The quest for efficient electrocatalysts to accelerate hydrogen evolution reaction (HER) is of immense importance for global sustainability. Transition-metal-based selenides, especially NiSe2, are considered as one of the most promising HER catalysts due to their cost-effectiveness and superior conductivity, yet their inherent activity is poor. Herein, we reasonably designed and synthesized self-supported fluorine-phosphorus dual-anion co-doped NiSe2 nanosheets grown on carbon cloth (F/P-NiSe2/CC) with excellent HER performance. The obtained F/P-NiSe2 only requires low overpotentials of 53 and 137 mV to obtain current densities of 10 and 50 mA cm–2, respectively, as well as a gentle Tafel slope of 95.6 mV dec–1, and can sustain at least 120 h operation in alkaline media. Experimental analyses and density functional theory calculations have cross-proven that the electronic configuration of NiSe2 is successfully modulated by co-doping, which effectively improves the conductivity, optimizes hydrogen adsorption energy (ΔGH*), and makes it easier to get over the rate-limiting obstacle. This work not only reveals the relationship between the structure and properties of electrocatalysts under the dianion synergistic regulatory strategy but also enlightens the design of advanced electrocatalysts.