In Situ Growth of Trimetallic FeCoNi Selenide Nanosheets on Nickel Foam for Electrocatalytic Water Splitting

Abstract

Metal selenides and their derivatives are regarded as potent electrocatalytic materials for the generation of hydrogen and oxygen as green energy through electrochemical water splitting. In situ growth of electrocatalysts is one of the promising methods to achieve high stability for electrocatalysts, wherein simultaneous cation doping could efficiently improve the active sites towards electrochemical water splitting. Herein, trimetallic FeCoNiSe₂ nanosheets (NSs) were prepared in situ on nickel foam by a hydrothermal method for the first time. The structural and morphological investigation confirms the formation of NiSe₂ NSs over nickel foam along with simultaneous doping of Fe and Co in the crystal structure of NiSe₂. The electrocatalytic efficiency of the synthesized materials was sequentially tested for HER, OER, and overall electrochemical water splitting. The trimetallic FeCoNiSe₂ NSs demonstrated high catalytic activity towards water electrolysis with a low cell voltage of 1.7 V at 100 mA cm^–2 compared to bimetallic FeNiSe₂, CoNiSe₂, and bare NiSe₂ NSs. Further, the electrocatalyst exhibits long-term stability for 40 h in 1 M KOH at 10 and 100 mA cm^–2 at 1.57 and 1.7 V, respectively. The enhanced electrocatalytic performance of trimetallic selenide nanosheets thus obtained through simultaneous doping and in situ growth on conducting metal substrates might open similar distinct approaches for developing more competent energy conversion and storage devices.