Unveiling the multifunctional role of Zn on Ni-B catalyst for alkaline hydrogen evolution reaction

Transition metal borides (TMBs) are considered promising electrocatalysts for alkaline hydrogen evolution reaction (HER), but their potential has not been effectively utilized due to their inherent activity and challenges in fine morphology regulation during chemical/electrochemical deposition processes. Here, we prepared Zn incorporated NiB catalyst (NZB) on nickel foam by a simple one-step chemical deposition combined with local dealloying method. It was revealed that Zn incorporation plays a multifunctional role in the activity and stability of NZB catalysts towards alkaline HER. The partial leaching of Zn regulated the microstructure of the NZB, while residual Zn optimized the electronic structure of the NZB catalyst, improving the interaction between the catalyst and HER intermediates, thereby simultaneously increasing the number of active sites and intrinsic activity. Furthermore, we found the introduction of Zn accelerated the completion of surface reconstruction and improved the crystallinity of catalysts, resulting in enhanced chemical and mechanical stability. These findings provide key insights into maximizing the potential of transition metal-based catalysts for HER.