N-doped CoSe2 nanomeshes as highly-efficient bifunctional electrocatalysts for water splitting

CoSe2 has been as one of promising electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) due to its earth-abundant resource, and tunable electronic structure. However, enhancing electrocatalytic activity of CoSe2 to meet the large-scale practical applications is desirable. Herein, we report a facile plasma nitridation strategy to generate N-doped CoSe2 nanomesh arrays on commercial carbon paper (N-CoSe2@CP). The obtained N-CoSe2@CP electrodes combined advantages of abundant electrochemical active sites and beneficial electronic structures, thus exhibiting a low overpotential of 106 mV and 237 mV to drive 10 mA cm−2 towards HER and OER in alkaline medium, respectively. Moreover, it can be employed as bifunctional electrocatalyst for overall water splitting, where a small potential of 1.57 V was required to reach 10 mA cm−2, and long-term stability was also realized. This work develops a promising strategy to explore highly-efficient nanocatalysts towards new energy conversion.