Nickel selenide from single-molecule electrodeposition for efficient electrocatalytic overall water splitting

Abstract

The preparation of highly active, low cost and stable electrocatalysts via simple and mild methods for overall water splitting is significant for energy conversion and storage. Herein, we used a nickel selenite complex [{Ni(TMEDA)SeO₃}₂] to obtain NiSe nanospheres on three-dimensional carbon cloth via electrodeposition. The performance of the as-prepared electrodes (NiSe-TMEDA/CC) was investigated in alkaline solution for water splitting, exhibiting bifunctional OER and HER activity with small overpotentials of 226 and 30.8 mV to achieve a current density of 100 mA cm⁻², respectively. Using this bifunctional electrode, a water electrolyzer only required a cell voltage of 1.52 V to deliver a current density of 100 mA cm⁻² with excellent long term stability. Compared with the traditional separate Ni and Se sources, the single-molecule precursor is beneficial to form uniform NiSe on the substrate. This work provides a reference for the preparation of bifunctional electrocatalysts for water splitting via single molecule electrodeposition.