Self-supported nanoporous cobalt phosphosulfate electrodes for efficient hydrogen evolution reaction.

• The CoP|S has coral-like nanoporous structures and allows the release of gas evolution in nano-scale design. • Stable nanoporous CoP|S with abundant active sites are fabricated through a simple annealing method. • S-substituting can control the electronic structure and favor more suitable H adsorption of CoP|S to promote HER activity. • Nanoporous CoP|S electrodes present the improved HER performance compared with CoP. The morphology and crystallographic surface can influence the catalytic HER activity of electrocatalyst. With sufficient active sites and surface area, nanoporous materials with three-dimensional interconnected porous networks have shown the promising application in electrocatalyst. In this work, we report a simple method that can synthesize the self-supported nanoporous cobalt phosphosulfate (CoP|S) electrocatalyst. Theoretical calculation shows that the phosphorus substitution by sulfur can control the electronic structures of the active sites and accelerate charge transfer of CoP, therefore improving HER activity. The experimental study shows that nanoporous CoP|S electrodes present the improved HER performance compared with CoP in alkaline media and acidic media, respectively. [ABSTRACT FROM AUTHOR]