Boron-doped CoSe2 nanowires as high-efficient electrocatalyst for hydrogen evolution reaction

Abstract

High activity and stable hydrogen evolution reaction (HER) catalysts have an indispensable influence on hydrogen production. Pyrite cobalt selenide (CoSe2) is considered an excellent non-noble metal compound HER catalyst due to its low price and excellent electrical conductivity. However, the HER catalytic activity of CoSe2 is still not ideal because of the weak adsorption of hydrogen on its active Co site. The anion introduction can improve the electronic structure of the catalyst and thereby enhance the performance of HER. Here, we report that B-doped CoSe2 nanomaterials on carbon cloth (B-CoSe2/CC) were successfully synthesized. Compared with CoSe2, B-CoSe2 exhibits better HER performance in 1 M KOH. The overpotential of B-CoSe2 catalyst is only 153 mV at 10 mA cm−2. Tafel slope of B-CoSe2/CC sample is only 85 mV dec−1. In addition, B-CoSe2/CC exhibits perfect long-term durability and cycle stability. Density functional theory (DFT) calculations illustrate that the doping of B improves the intrinsic conductivity of CoSe2 and optimizes the hydrogen adsorption free energy (ΔGH*) of Se and Co sites. This work not only proposes a new anion doping strategy to improve the electronic structure of cobalt-based selenides for improved HER performance, but also provides a reference for the screening and design of other transition metal compound HER electrocatalysts.