Photocatalytic degradation of tetracycline based on the highly reactive interface between graphene nanopore and TiO2 nanoparticles

The development of TiO2-based composites with a broad light response and outstanding photocatalytic performance is very important for the removal of antibiotics. In this work, we prepared a series of new porous graphene (PG)/TiO2 nanocomposites formed the different highly reactive interface within confined space via a partial combustion strategy using TiCl4 as the Ti source. The as-prepared PG/TiO2 exhibited the simultaneous effect of incredible adsorptivity and photodegradation performance toward tetracycline (TC) antibiotic under UV and visible light in contrast to conventional PG/TiO2, pure TiO2 (P25) and PG. Optimization experiments showed that PG/TiO2-4% had the optimal removal performance among all the nanocomposites. The removal rate of TC reached up to 95.5%, which was 15% higher than that of I-PG/TiO2 and 25% higher than that of P25 within 90 min. The results were credited to (1) the high specific surface area and porous structure of PG, (2) the broad light response range and rapid separation of h(+) and e(-) of PG/TiO2, and (3) the highly reactive interface between PG and TiO2 nanoparticles. In addition, active radical trapping experiments indicated that center dot O-2(-) was crucial to the elimination of TC. This work showed the new potential of PG/TiO2 nanocomposites for the enhanced photocatalytic performance.

Automated summary

The development of TiO2-based composites with broad light response and outstanding photocatalytic performance is crucial for the removal of antibiotics. In this study, a series of porous graphene (PG)/TiO2 nanocomposites with different highly reactive interfaces were prepared using TiCl4 as the Ti source. The optimized PG/TiO2-4% exhibited the best removal performance among all the nanocomposites, achieving a higher removal rate of tetracycline antibiotic compared to conventional PG/TiO2, pure TiO2 (P25), and PG. The results were attributed to the high specific surface area and porous structure of PG, the broad light response range and rapid separation of charges in PG/TiO2, and the highly reactive interface between PG and TiO2 nanoparticles.