A three-dimensional coral-like Zn,O-codoped Ni3S2 electrocatalyst for efficient overall water splitting at a large current density

The synergistic achievement of geometrical optimization and electronic structure adjustment of electrocatalysts is significant to accelerate the efficiency of overall water splitting. Herein, we report a three-dimensional coral-like Zn,O-codoped Ni3S2 nanostructure grown on nickel foam (denoted as ZO-Ni3S2/NF) by a facile solvothermal method. We show that the introduction of Zn2+ can not only trigger the generation of a three-dimensional coral-like nanoarchitecture of Ni3S2/NF with a larger catalytically active area, but also increases the number of active Ni3+ sites in ZO-Ni3S2/NF, which enhances the adsorption capacity of intermediates in the oxygen evolution reaction (OER) process. Moreover, the O-doping endows Ni3S2 with improved intrinsic electronic conductivity and thus facilitates fast charge transfer during the hydrogen evolution reaction (HER). As expected, ZO-Ni3S2/NF exhibits excellent electrocatalytic performance, requiring only 235 mV and 450 mV to deliver 500 mA cm(-2) for the HER and OER, respectively. The findings in our work provide new insights for the development of highly active and stable noble-metal-free electrocatalysts at high current density for industrial hydrogen fuel production.

Automated summary

The introduction of Zn2+ and oxygen doping into a three-dimensional coral-like Zn,O-codoped Ni3S2 nanostructure grown on nickel foam enhances catalytic activity and increases active sites, while also improving intrinsic electronic conductivity of Ni3S2 for faster charge transfer during oxygen and hydrogen evolution reactions. As a result, the ZO-Ni3S2/NF electrocatalyst exhibits excellent performance for both oxygen and hydrogen evolution reactions at high current densities.