A Hollow Flower-Like Ti3C2@TiO2/G-C3N4 Z-Scheme Heterojunction for Effective Visible-Light-Driven Tetracycline Degradation

Efficient interfacial carrier transfer and separation can effectively enhance photocatalytic activity. In this study, a high-performance Z-scheme Ti 3 C 2 @TiO 2 /g-C 3 N 4 (TCTCN) ternary photocatalyst possessing a hollow flower-like architecture was synthesized using a reliable and effective method. Ti 3 C 2 @TiO 2 heterojunctions were constructed because exfoliated Ti 3 C 2 was partially oxidized to TiO 2 during the formation of hollow g-C 3 N 4 flower-like microspheres. In the Z-scheme heterojunction, the highly conductive metallic Ti 3 C 2 layers functioned as solid-state electron mediators, promoting electron–hole separation and migration efficiency. Under visible-light irradiation, the as-synthesized TCTCN photocatalyst possessed outstanding photocatalytic tetracycline (TC) degradation efficiency that was 2.03-fold and 1.25-fold higher than those of individual layered and hollow flower-like g-C 3 N 4 , respectively. The excellent photocatalytic TC degradation efficiency is attributed to the unique hollow structure and synergy among the Ti 3 C 2 , TiO 2 and g-C 3 N 4 structures in the TCTCN composite, enabling the Z-scheme-mechanism-assisted rapid separation and slow recombination of photoinduced electron–hole pairs because of the increased photocatalytic activity. Moreover, the TCTCN ternary hybrid photocatalysts possessed good physical stability and reusability, and the TC degradation efficiency negligibly decreased after five cycles. This work is an important development to establish a sound foundation for designing g-C 3 N 4 -based hybrid photocatalysts possessing substantial charge carrier separation and transfer for efficiently degrading antibiotics.