A two-dimensional heterogeneous structured Ni3Se2@MoO3 catalyst for seawater electrolysis

Abstract

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 Ni₃Se₂@MoO₃ composite (Ni₃Se₂@MoO₃/CF) catalyst is synthesized by a facile one-step electrodeposition method. The prepared Ni₃Se₂@MoO₃/CF catalyst demonstrates impressive activity and stability toward both the oxygen evolution reaction (OER) and hydrogen evolution reaction. The OER overpotential of Ni₃Se₂@MoO₃/CF is 280 mV at 100 mA cm⁻², which is much lower than that of the commercial RuO₂ 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 MoO₃ particles tightly grown on the edges of Ni₃Se₂ nanosheets, resulting in a large specific surface area, abundant active sites, and enhanced durability.