Fe/P dual doping boosts the activity and durability of CoS2 polycrystalline nanowires for hydrogen evolution

Abstract

High activity and stability are two requisites for a high-performance electrocatalyst but usually have to be balanced. CoS₂ is regarded as an alternative electrocatalyst for the hydrogen evolution reaction (HER) but its HER activity and durability still cannot meet the criteria for practical applications. Here, we develop a strategy to simultaneously boost the HER activity and durability of CoS₂ by fabricating polycrystalline nanowire (PCNW) arrays with dual doping of Fe and P. Systematic investigations demonstrate that Fe incorporation increases the active sites, while P substitution significantly boosts chemical and mechanical stability as well as HER kinetics. PCNW arrays provide abundant accessible active sites and allow for prompt gas release. As a result, Fe/P-CoS₂ PCNW exhibits excellent HER performance with a low overpotential of 80 mV at 10 mA cm⁻² and robust durability in acidic media. Such a strategy may provide opportunities for designing efficient and durable HER electrodes for practical water splitting.