Fabricating MoO3/g-C3N4 Heterojunctions with Radio Frequency Plasma for Enhanced Photocatalytic Dehydrogenative Coupling Reactions: A Sustainable Light-Driven Platform for P–S/C Bond Construction

MoO3/g-C3N4 heterojunctions were successfully fabricated by radio frequency (RF) plasma instead of a conventional calcination method for the first time. The excellent photocatalytic reactivity of RF plasma-treated MoO3/g-C3N4 heterojunctions (abbreviated as P-MOCN) was demonstrated by the coupling reactions between thiol compounds or heterocyclic aromatics and P(O)−H compounds. In the presence of P-MOCN as photocatalysts, various phosphorothioate derivatives or phosphorylated heterocyclic aromatics could be obtained in good yields with O2 in the air as a green oxidant, without the addition of bases, additives, or external oxidants. In addition, the P-MOCN also exhibited gram-scale reactivity, good stability, reusability, and satisfactory photocatalytic activity under sunlight irradiation. The mechanism study implied that the generated P-centered radical induced by the single electron transfer (SET) pathway was crucial for the success of the reaction. The enhanced photocatalytic oxidative dehydrogenative performance was attributed to the presence of more oxygen vacancies, enhanced electron density, and the increased active sites induced by RF plasma treatment. This work reveals that P-MOCN are competitive candidates as visible-light-responsive catalysts to realize oxidative dehydrogenative coupling reactions, providing a novel and sustainable method to prepare heterojunctions as photocatalysts.