Soft-template derived Ni/Mo2C hetero-sheet arrays for large current density hydrogen evolution reaction.

ABSTRACT

Practical structural design and electronic regulation are significant for synthesising efficient electrocatalysts. Therefore, a facile soft-template approach has been applied to successfully grow Ni/Mo2C heterojunction nanosheet arrays on nickel foam (NF) skeleton (NS-Ni/Mo2C@NF) using polyvinylpyrrolidone (PVP) as a soft template. The density functional theory (DFT) calculations reveal that abundant Ni/Mo2C heterojunction in NS-Ni/Mo2C@NF can provide many active sites with a moderate hydrogen adsorption free energy (ΔGH*, 0.037 eV). Benefiting from this nanosheet array structure and abundant Ni/Mo2C heterojunctions, the NS-Ni/Mo2C@NF catalyst can efficiently catalyze HER, especially at large current densities. As a result, only 151 and 271 mV overpotentials are needed to deliver 100 and 1000 mA/cm2 HER, respectively. More importantly, the hydrogen production testing with NS-Ni/Mo2C@NF as the working electrode can run stably for 500 h without activity decay under the current density of 500 mA/cm2 commonly used in industrial water electrolyzers, indicating that NS-Ni/Mo2C@NF has broad application prospects.