Zn-VOx-Co nanosheets with amorphous/crystalline heterostructure for highly efficient hydrogen evolution reaction

Designing cost-effective catalysts with high-activity and ultra-stability for hydrogen evolution reaction (HER) is important in the scaling-up of water electrolysis process for hydrogen production. Herein, a Zn-VOx-Co two-dimensional (2D) nanosheet with well-integrated heterostructure was successfully synthesized on carbon fiber paper (CFP) by a facile electrodeposition approach. Interestingly, the obtained nanosheets composed of amorphous VOx-Co and Zn-Co crystalline phases with a heterostructure. Density functional theory (DFT) calculations reveled that the dual-doping of Zn and VOx optimized d-band center of Co and balanced adsorption and desorption of H, which enhanced intrinsic electrocatalytic HER activity. As a result, the optimum catalyst achieved a current density of 10 mA cm−2 at an overpotential as low as 46 mV and long-term electrochemical stability over 36 h in 1 M KOH solution. This work opens a new avenue for designing electrocatalysts with unique crystalline-amorphous heterostructure by dual-doping to achieve tunable surface properties as well as d-band structure.