Porous NiCo Diselenide Nanosheets Arrayed on Carbon Cloth as Promising Advanced Catalysts Used in Water Splitting

we report the synthesis of porous NiCo diselenide nanosheets arrayed on carbon cloth (CC) via ion exchange with a hydroxide precursor. This bind-free three-dimensional (3D) architecture possesses the huge specific surface area and facilitates ion transport and charge transfer, leading to a superior performance in water splitting as a bifunctional catalyst for both H2 and O2 evolution reaction (HER and OER). The as-prepared NiCo diselenide/CC composites show a high HER capability in 0.5 M H2SO4 solution with a Tafel slope as small as 31.6 mV·dec−1. They offer a HER current of 10 mA·cm−2 at a low overpotential of 108 mV. Their OER efficiency is also remarkable in 1 M KOH solution with a small Tafel slope of 42.3 mV·dec−1 and a low overpotential of 258 mV at 10 mA·cm−2. This 3D porous NiCo diselenide nanosheet array holds a promise as an attractive alternative to precious catalysts of water splitting with high activity and long-term stability.