Preparation of Fe‐Doped Ni3S2/Ni(OH)2/Ni/NSG Composites and Enhanced Water Splitting Performance

Abstract

Herein, Fe‐doped Ni3S2/Ni(OH)2/Ni@NSG electrocatalysts are prepared by dealloying Ni–Al precursors followed by magnetic stirring. It is found that the hydrogen precipitation reaction (HER) of NSG‐Fe‐25 is 148 mV at a current density of 10 mA cm−2 and the oxygen evolution reaction (OER) is 274 mV at a current density of 50 mA cm−2 compared to NSG‐Fe‐5, NSG‐Fe‐45, Ni‐NN‐Fe, and Ni‐NN‐Fe@NSG. The Tafel slopes for the HER are 81.6 mV dec−1, and the Tafel slope of OER is 61.6 mV dec−1, while the Cdl value of NSG‐Fe‐25 is larger and the resistance value is smaller. Therefore, NSG‐Fe‐25 has the optimal performance. The heterostructure of Fe‐doped Ni3S2/Ni(OH)2/Ni@NSG provides abundant active sites for surface HER and OER, which enhances the electronic conductivity of the electrode. Meanwhile, long‐term constant‐current electrolysis test experiments show that NSG‐Fe has good stability in use. The present study opens a new window for the design and preparation of total hydrolysis electrocatalysts.