Anchoring Ni single atoms on sulfur-vacancy-enriched ZnIn2S4 nanosheets for boosting photocatalytic hydrogen evolution

Structure manipulation of photocatalysts at an atomic scale is a promising way to improve its photocatalytic performance. Herein, we realize the anchoring of single Ni atoms on the ZnIn2S4 nanosheets with rich sulfur vacancies. Experimental results demonstrate that single Ni atoms induce the formation of Ni-O-M (Zn/In) atomic interface, which can efficiently promote the carriers separation and prolong the carrier life time. In addition, in situ electron spin resonance spectroscopy (ESR) confirms that the single Ni atoms act as an electron trapping center for protons reduction. As a result, the single Ni atoms decorated ZnIn2S4 nanosheets with rich sulfur vacancies (Ni/ZnIn2S4-RVs) shows a hydrogen evolution rate up to 89.4 μmol h−1, almost 5.7 and 2.3 times higher compared to that of ZnIn2S4 nanosheets with poor sulfur vacancies and rich sulfur vacancies (denoted as ZnIn2S4-PVs and ZnIn2S4-RVs). This work opens up a new perspective manipulating the single-atom cocatalyst and sulfur vacancy on sulfide supports for improving photocatalytic hydrogen evolution.