Boosting interfacial charge transfer for alkaline hydrogen evolution via rational interior Se modification

For electrocatalytic hydrogen evolution reaction (HER) in alkaline media, it is urgently needed to accelerate the generation of H*. Here, using Se doped phosphides inside nitrogen doped carbon (skin-core structure) as catalysts, the HER performance in alkaline electrolyte was improved. The overpotential of 261 mV at 400 mA cm(-2) was among the top level reported so far. Based on the combination of experimental results and density functional theory (DFT) calculations, the interior CoSe phase generated by Se modification provides faster charge transfer from the inner to carbon layer, facilitating the rate-determining step (Volmer). Also, the needle-like nanowire array facilitates the H-2 desorption at a large current density. Furthermore, a solar-to-hydrogen efficiency up to 10.2% was demonstrated. This work may provide an effective strategy to boost the reaction kinetics via accelerating interfacial charge transfer ability of electrocatalysts.

Automated summary

By using Se-doped phosphides inside nitrogen-doped carbon as catalysts, this study successfully improved the performance of electrocatalytic hydrogen evolution reaction in alkaline media. Experimental and theoretical calculations showed that the CoSe phase generated by Se modification facilitated faster charge transfer and optimized the rate-determining step, enhancing the reaction kinetics of the catalyst.