Tetragonal transition metal selenide for hydrogen evolution

Hydrogen evolution reaction (HER) plays an important role in energy conversion through water splitting to produce hydrogen. Considering the large surface/volume ratio, exploration of two-dimensional materials with high-efficient basal plane has attracted a great enthusiasm in designing electrocatalysts. Herein, tetragonal copper selenide (CuSe) was identified as a promising candidate toward HER by density functional theory calculations. The low exfoliation energy Eexf of 41.47 meV/Å2 ensures the exfoliation of CuSe monolayer along [0 0 1] direction, which allows the exposure of the basal plane. More importantly, the pristine CuSe monolayer without any treatment delivers relatively good activity, as reflected by the small thermodynamic barrier of 0.3 eV. Furthermore, CuSe possesses good electron conductivity, which makes it beneficial to the electron transfer during electrocatalysis. Therefore, these results indicate that CuSe acts as a promising material for the next-generation HER catalysis with the high basal utilization.