Crystalline F-doped titanium dioxide nanoparticles decorated with graphene quantum dots for improving the photodegradation of water pollutants

Abstract

Carbon dots are emerging photoactive materials with high chemical stability, aqueous solubility, abundant surface functional groups and low-cost production. Their great advantages, incorporated into the high photocatalytic activity of the TiO2, result in hybrid systems that overcome some of the photocatalytic drawbacks associated with TiO2. In this work, a facile synthesis of hybrids of F-doped TiO2 and N-doped graphene quantum dots (F-TiO2@N-GQDs) is reported. These systems have demonstrated efficient photocatalytic properties in light-driven pollutant reduction from water. Therefore, using a simple and low-cost synthesis method, the N-GQDs act as electron reservoirs improving the pairs e--h+ lifetime in TiO2 by decreasing charge recombination, increasing their photocatalytic capacity. The photocatalysts showed very effective degradations of different contaminants such as methylene blue (90% degradation) ciprofloxacin (62% degradation) and naproxen (60% degradation) in short periods of up to 15 min and 4-chlorophenol (59% degradation) in 30 min using UV light (300 W).