Modulating charge carrier transfer channel by 2D/2D Schottky heterojunction of Ti3C2/BiOIO3 for effective photocatalytic degradation of typical antibiotics

Constructing two-dimensional (2D)/2D Schottky heterojunction using Ti3C2 with n-type semiconductors has a great potential in photocatalysis field owing to the improved separation and transfer ability of photogenerated charges. However, an in-depth exploration of electron transfer behavior in the Schottky heterojunction using Ti3C2 with n-type semiconductor is still lacking, thus hindering the development of Ti3C2 based Schottky heterojunction. Herein, 2D/2D Schottky heterojunction of Ti3C2/BiOIO3 was successfully fabricated with improved photocatalyst efficiency. With the Schottky junction formation between Ti3C2 and BiOIO3, 3 wt% Ti3C2/BiOIO3 exhibited superior ciprofloxacin photodegradation performance (94.11 % within 60 min). In situ X-ray photoelectron spectroscopy and ultraviolet photoemission spectroscopy reveals that the enhanced performance could be ascribed to one-way carrier transfer channel for preventing the carrier recombination and remarkably prolonging the carrier lifetime through Schottky heterojunction. Meanwhile, in the Schottky heterojunction, the 2D ultrathin structures and plentiful interfaces not only offer abundant channels for photogenerated charges migration, but also promote mass transfer. In addition, the toxicity estimation software tool analysis demonstrates that the toxicity of most intermediates was lower than ciprofloxacin. The work provides an in-depth understanding of the photocatalytic mechanism of typical antibiotics degradation, and offers an idea for the exploitation of highly active Schottky heterojunction photocatalysts.