Developing low-cost, high performance, stable non-noble bifunctional electrocatalysts for overall water splitting is of great importance for future energy supplement. Despite recent advances in the synthesis of transition metal selenide nanostructures, the fabrication of porous nanosheet based binder-free electrode with more active sites remains a major challenge. Herein, the self-templating construction of a porous CoSe2 nanosheet array on carbon cloth (p-CoSe2/CC) has been reported by vapor selenizing the preprepared α-Co­(OH)2 nanosheet array precursor. Arising from large active surface area, fast diffusion of generated gas and strong structural stability, the as-obtained p-CoSe2/CC can serve as an efficient bifunctional electrocatalyst for both OER and HER in alkaline electrolyte, with a current density of 10 mA cm–2 at overpotential of 243 mV for OER and 138 mV for HER, respectively. Moreover, when p-CoSe2/CC is assembled as an alkaline electrolyzor, it only needs a cell voltage of 1.62 V at 10 mA cm–2 and shows excellent long-term stability of 20 h. The versatile fabrication strategy with self-templated porous structure proves a new way to construct other advanced metal selenide for energy conversion and storage.

Sulfur vacancy-tailored NiCo2S4 nanosheet arrays as efficient electrocatalysts for the hydrogen evolution reaction at all pH values.

Self-supported binary hybrid heterogeneous CoFe LDH/Co0.85Se nanosheet array catalyst for efficient oxygen evolution reaction.

The development of efficient, stable and low-cost oxygen evolution reaction (OER) catalysts in anodes is essential for the production of hydrogen resources by electrolyzing water. Cobalt hydroxide (α-Co(OH)2) is one...

An ultrathin carbon-coated CoO composite catalyst grown on carbon cloth was developed for efficient alkaline HER.