Encapsulating N‑doped graphite carbon in MoO2 as a novel cocatalyst for boosting photocatalytic hydrogen evolution

Generally, it is important to ameliorate the co-catalyst used in photocatalytic hydrogen evolution reactions (PHERs) to achieve efficient transfer and separation of photogenerated carriers, decrease the surface reaction energy barrier, and hence improve the photocatalytic activity . In this study, N-doped graphite carbon (GC) was introduced in situ to MoO 2 to ensure the presence of well-dispersed active sites, lower the overpotential of hydrogen evolution, and further achieve high conductivity. Then, the MoO 2 /GC composite obtained was used as a co-catalyst of ZnIn 2 S 4 (ZIS) in a PHER, resulting in a great improvement in the photocatalytic activity. Given the metallicity and large work function of MoO 2 /GC, a Schottky interface can form between MoO 2 /GC and ZIS, which accelerates the transmission of photogenerated electrons. As a result, the separation efficiency of photogenerated carriers improves, whereas the surface overpotential of PHERs clearly decreases for ZIS. This study proposes a new idea for exploiting efficient co-catalysts and promotes the wide and heavy use of carbon materials in the field of solar energy conversion .