Tungsten doping generated Mo2C-MoC heterostructure to improve HER performance in alkaline solution

Renewable hydrogen energy has been regarded as ideal green energy. There is an urgent need for efficient and stable non-noble metal electrocatalysts for hydrogen evolution reaction (HER). Molybdenum carbide (MoxC) has excellent intrinsic activity and stability, which is expected as one of the ideal candidates to replace Pt. Herein, we report a facile Tungsten (W) doping method to regulate the crystal structure of MoxC to generate a Mo2C-MoC heterostructure. It reduces the charge transfer resistance and regulates adsorption and desorption of hydrogen, thereby promoting the HER in alkaline solution. Besides, the carbon matrix not only increases the conductivity, but also protects the active site of W-MoxC/C from agglomeration and deactivation due to high temperature. Under alkaline media, the W-MoxC/C has improved HER catalytic activity. In 1 M KOH, an overpotential of 178 mV is required to reach a current density of 10 mA cm−2, and the Tafel slope is 54.3 mV dec−1. Moreover, it has a small charge transfer resistance and good stability. This work develops a multi-effect doping method that generates heterostructure and increases the active sites, which providing a new strategy for the performance regulation of other electrocatalysts.