Layered mesoporous TiO2 loaded CQDs activation of periodate to remove sulfamethoxazole: Key role of CQDs

Titanium dioxide (TiO 2 ) stands out as a promising semiconductor catalyst in photocatalysis, mainly due to its low cost and high photocatalytic activity. However, the photocatalytic efficiency of TiO 2 is limited by the fast rate of photogenerated electron-hole recombination. In this paper, carbon quantum dots (CQDs) are used to address the issue of electron-hole recombination in TiO 2 . SEM, TEM, XRD, and Raman spectroscopy confirmed that CQDs was successfully loaded onto LM-TiO 2 . Sulfamethoxazole (SMX) was selected as a simulated water pollutant under ultraviolet irradiation. Under ultraviolet irradiation, loaded CQDs onto layered mesoporous TiO 2 (CQDs@LM-TiO 2 ) exhibits superior activity in degrading SMX compared with pure LM-TiO 2 . Quenching, EPR and probe experiments showed that the dominant active species of UV/CQDs@LM-TiO 2 /PI system was single oxygen ( 1 O 2 ). The results of electrochemical characterization, FT-IR and XPS show that the CQDs on the surface of LM-TiO 2 is conducive to the transfer of electrons, thus activating PI to produce 1 O 2 and degrading pollutants. The cyclic and coexisting anion influence experiments show that the catalyst has excellent stability, and the UV/CQDs@LM-TiO 2 /PI system is resistant to co-existing substances in water. Owing to their unique electron transport capacity and wide light response interval, CQDs show great application potential in the field of photocatalysis.