Charge redistribution enabling Ru/W5N4 heterojunction electrocatalyst for highly efficient alkaline hydrogen production

The development of electrocatalysts capable of efficiently catalyzing the alkaline hydrogen evolution reaction (HER) is crucial for driving the advancement of sustainable energy. Herein, by altering the surface state of the support, we transformed the bulk W5N4 into a porous structure and constructed a Ru/W5N4 heterostructure. The transfer of electrons from Ru to W5N4 can optimize the electronic structure of the catalyst, thereby effectively promoting electron transfer, accelerating reaction kinetics, and enhancing the activity of the catalyst. Furthermore, W5N4 can serve as a protective shell to stabilize Ru0, which is regarded as the active center in HER. The resulting Ru/W5N4 exhibits excellent HER activity, requiring only overpotentials of 43 and 156 mV to achieve current densities of −10 and −100 mA cm−2, respectively. This work provides valuable insights into the rational construction of heterostructures to optimize HER performance.