In situ constructed oxygen-vacancy-rich MoO(3−x)/porous g-C(3)N(4) heterojunction for synergistically enhanced photocatalytic H(2) evolution

A simple method was developed for enhanced synergistic photocatalytic hydrogen evolution by in situ constructing of oxygen-vacancy-rich MoO(3−x)/porous g-C(3)N(4) heterojunctions. Introduction of a MoO(3−x) precursor (Mo(OH)(6)) solution into g-C(3)N(4) nanosheets helped to form a porous structure, and nano-sized oxygen-vacancy-rich MoO(3−x)in situ grew and formed a heterojunction with g-C(3)N(4), favorable for charge separation and photocatalytic hydrogen evolution (HER). Optimizing the content of the MoO(3−x) precursor in the composite leads to a maximum photocatalytic H(2) evolution rate of 4694.3 μmol g(−1) h(−1), which is approximately 4 times higher of that of pure g-C(3)N(4) (1220.1 μmol g(−1) h(−1)). The presence of oxygen vacancies (OVs) could give rise to electron-rich metal sites. High porosity induced more active sites on the pores' edges. Both synergistically enhanced the photocatalytic HER performance. Our study not only presented a facile method to form nano-sized heterojunctions, but also to introduce more active sites by high porosity and efficient charge separation from OVs.