Construction of iron oxyhydroxide/nickel sulfate hydroxide hybrid electrocatalyst for efficient oxygen evolution

Abstract

Transition metal (TM) basic salts have been recognized as high-efficiency catalysts for electrocatalytic oxygen evolution reaction (OER), which is of great importance for producing clean hydrogen energy. Herein, novel OER electrocatalyst consisting of iron oxyhydroxide/nickel sulfate hydroxide nanobelts loaded on nickel foam (FeOOH/NiSH/NF) is reported, synthesized via a facile solvothermal-hydrolysis method. Impressively, the optimized FeOOH/NiSH/NF catalyst exhibits outstanding performance, requiring only a low overpotential of 265 mV to drive a current density of 50 mA·cm−2 for OER in alkaline media. Structure evolution of the catalysts under the OER process has been investigated through multiple characterization methods, and SO42− adsorbed FeOOH/NiOOH is demonstrated to be the true active species. The essential role of incorporated FeOOH has been further elucidated by using density functional theory (DFT) calculations. This work not only reports a novel NiSH-based catalyst towards OER, but also provides insights for understanding the structure–property of TM basic salt-based hybrid OER catalysts. Graphic abstract: (Figure presented.)