Mesoporous TiO2/g-C3N4 composites with O-Ti-N bridge for improved visible-light photodegradation of enrofloxacin.

g-C3N4 makes good prospects in photocatalytic field due to its two-dimensional (2D) structure and visible-light activity. How to improve its photocatalytic activity by minimizing the unexpected recombination of photo-induced charge carries on g-C3N4 motivates our research. Herein, mesoporous TiO2/g-C3N4 composites are fabricated with 2D TiO2(B) nanosheets regulating thermal condensation process of g-C3N4 nanosheets. FT-IR and XPS results suggest that the formation of O-Ti-N chemical bond increases the percentage of N-(C)3 in the conjugated system, accelerating the transportation of photo-induced electrons. The optical property and PL results illustrate that the formed interface heterojunction with chemical bond facilitates the separation and transfer of photo-induced charge carriers. Hence, the removal constant of TiO2/g-C3N4 composites is 46.3 times higher than that of g-C3N4. This study opens up a new insight into the development of composite materials in the field of organic pollutant treatment.