Facile synthesis of hierarchical porous NiCoSeO networks with controllable composition as a new and efficient water oxidation catalyst.

Electrocatalysts are of significant importance for hydrogen production via water splitting. To replace noble metal based electrocatalysts, exploring new counterparts is critical for their large-scale and widespread deployment. In this paper, we report the synthesis of nickel-cobalt selenite (Ni0.5Co0.5SeO3) networks on nickel foam with promising electrocatalytic performance through a facile electrodeposition method. The networked structure built with interconnected nanosheets along with the three-dimensional backbone of nickel foam is able to provide a large surface area for the reaction to take place and simultaneously offer connected channels for charge carriers to pass through, consequently realizing the enhancement of oxygen evolution reaction (OER) electrocatalytic activity. Importantly, the hierarchical channel structure affords vast spaces to buffer the volume change during repeated redox reactions and offers feasible channels for gas release, leading to good electrochemical stability. The best sample with an optimized composition shows superior catalytic activity with a high current density of 243.6 mA cm-2 at an overpotential of 500 mV and excellent stability.