constructed oxygen-vacancy-rich MoO /porous g-CN heterojunction for synergistically enhanced photocatalytic H evolution.

A simple method was developed for enhanced synergistic photocatalytic hydrogen evolution by constructing of oxygen-vacancy-rich MoO /porous g-CN heterojunctions. Introduction of a MoO precursor (Mo(OH)) solution into g-CN nanosheets helped to form a porous structure, and nano-sized oxygen-vacancy-rich MoO grew and formed a heterojunction with g-CN, favorable for charge separation and photocatalytic hydrogen evolution (HER). Optimizing the content of the MoO precursor in the composite leads to a maximum photocatalytic H evolution rate of 4694.3 μmol g h, which is approximately 4 times higher of that of pure g-CN (1220.1 μmol g h). 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.