He plus beam irradiation boosting electrocatalytic performance of NiS2 nanosheets for hydrogen evolution reaction

Hydrogen evolution by water splitting is one of the most popular methods in the new generation energy exploration. During the hydrogen evolution reaction (HER), NiS2, which is an electrochemical catalyst, has been widely investigated. However, the electrochemical catalytic performance of NiS2-based catalysts is still dissat-isfied due to their relatively poor intrinsic catalytic activities. Herein, we introduced vacancies into NiS2 nanosheets and the activation of initial inert sulfur sites by He+ ion irradiation (at a dose of 1 x 1015/cm2) to improve the HER electrocatalytic performance of NiS2. Additionally, density functional theory (DFT) calculations were adopted. Clearly, the intrinsic vacancies (both Ni and S vacancies) of NiS2 can reduce the band gap of NiS2 and improve its electron transfer efficiency in the HER process. This work provides a candidate strategy for NiS2- based electrocatalysts to optimize HER performance.

Automated summary

In this study, vacancies were introduced into NiS2 nanosheets and initial inert sulfur sites were activated by He+ ion irradiation to improve the electrocatalytic performance of NiS2-based catalysts. DFT calculations confirmed that the intrinsic vacancies in NiS2 can enhance electron transfer efficiency in the HER process.