Interface engineering and nanoconfinement strategies to synergistically enhance hydrogen evolution in acidic and basic media

As a potential catalyst for hydrogen evolution reaction (HER), tungsten nitride (W 2 N) has attracted extensive attention, due to its Pt-like characteristic. Nevertheless, insufficient active sites, slow electron transfer, and lack of scale-up nano-synthesis methods significantly limit its practical application. Constructing multi-component active centers and interface-rich heterojunctions to increase exposed active sites and modulate interface electrons is a very effective modification strategy. Therefore, a nano-heterostructure formed from tungsten nitride, tungsten phosphide and tungsten encapsulated in N, P co-doped carbon nanofiber (W 2 N/WP/W@NPC) was synthesized by a flexible and scalable electrospinning technology. Experimental results reveal that abundant heterojunctions are formed, electron transfer occurs between tungsten nitride and tungsten phosphide, and carbon nanofibers play a confinement role. The optimized W 2 N/WP/W@NPC-3 electrocatalyst demonstrates excellent HER catalytic activity and robust stability in both acidic and base media. Furthermore, the overall water splitting performance is tested using W 2 N/WP/W@NPC as the cathode through a two-electrode electrolyzer, which also exhibits impressive electrochemical performance.