A two-dimensional heterogeneous structured NiSe@MoO catalyst for seawater electrolysis

Hydrogen production from seawater electrolysis is quite attractive while full of challenges due to the dissatisfactory stability and low selectivity. In this work, a copper foam (CF) supported Ni 3 Se 2 @MoO 3 composite (Ni 3 Se 2 @MoO 3 /CF) catalyst is synthesized by a facile one-step electrodeposition method. The prepared Ni 3 Se 2 @MoO 3 /CF catalyst demonstrates impressive activity and stability toward both the oxygen evolution reaction (OER) and hydrogen evolution reaction. The OER overpotential of Ni 3 Se 2 @MoO 3 /CF is 280 mV at 100 mA cm −2 , which is much lower than that of the commercial RuO 2 catalyst (371 mV). In addition, the catalyst is highly selective for the OER in alkaline seawater during the anodic reaction and exhibits robust durability with almost no activity loss after the durability test for more than 200 h. The good electrocatalytic performance of the prepared catalyst should be attributed to the MoO 3 particles tightly grown on the edges of Ni 3 Se 2 nanosheets, resulting in a large specific surface area, abundant active sites, and enhanced durability. Ni 3 Se 2 @MoO 3 /CF catalysts were prepared by a one-step electrodeposition method, and the catalyst showed excellent stability at high current densities as a bifunctional catalyst for seawater electrolysis.