In situ constructed oxygen-vacancy-rich MoO3−x/porous g-C3N4 heterojunction for synergistically enhanced photocatalytic H2 evolution

• Published in: RSC advances Vol. 11; no. 50; pp. 31219 - 31225
• Main Authors: Pan, Yufeng, Xiong, Bin, Zha, Li, Wu, Yan, Yan, Chunjie, Song, Huaibin
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 22.09.2021; The Royal Society of Chemistry
• Subjects: Carbon nitride; Chemistry; Heterojunctions; Hydrogen evolution; Molybdenum trioxide; Oxygen; Photocatalysis; Porosity; Precursors; Separation; Vacancies
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d1ra05620d

A simple method was developed for enhanced synergistic photocatalytic hydrogen evolution by in situ constructing of oxygen-vacancy-rich MoO3−x/porous g-C3N4 heterojunctions. Introduction of a MoO3−x precursor (Mo(OH)6) solution into g-C3N4 nanosheets helped to form a porous structure, and nano-sized oxygen-vacancy-rich MoO3−xin situ grew and formed a heterojunction with g-C3N4, favorable for charge separation and photocatalytic hydrogen evolution (HER). Optimizing the content of the MoO3−x precursor in the composite leads to a maximum photocatalytic H2 evolution rate of 4694.3 μmol g−1 h−1, which is approximately 4 times higher of that of pure g-C3N4 (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.