2D/2D Mn0.5Cd0.5In2S4/g-C3N4 heterojunctions with controllable charge transfer pathways for effective photocatalytic H2 production and antibiotics removal

The separation efficiency of photoinduced electron-hole pairs has an important function in photocatalytic reactions. In this work, the MnxCd1−xIn2S4 solid solutions with tunable band edge positions were fabricated by a facile hydrothermal route. Benefit from the regulation of band edge positions, the charge migration is regulated from type-I mechanism (MnIn2S4/g-C3N4 and CdIn2S4/g-C3N4) to type-II mechanism (Mn0.5Cd0.5In2S4/g-C3N4), which boosts the separation efficiency of charge carriers for photocatalytic reactions. The fabricated Mn0.5Cd0.5In2S4/g-C3N4 nanocomposites exhibit superior photocatalytic hydrogen production and tetracycline hydrochloride (TCH) photodegradation as compared to the g-C3N4 nanosheets, MnIn2S4, CdIn2S4, as well as the Mn0.5Cd0.5In2S4 solid solution. Based on the XPS test and the determination of band edge position, the type-II heterojunction photocatalytic mechanism is proposed to illustrate the transfer path of the charge carriers. This work offers a newfangled perspective for exploring an effective photocatalytic system.