Highly enhanced adsorption and photocatalytic performance of TiO2 quantum dots synthesized by microwaves for degradation of reactive red azo dye

In this work, highly homogeneous TiO2 quantum dots (QDs) were synthesized and evaluated about their adsorption potential and applied as photocatalysts for the degradation of reactive red azo dye (RR141). QDs were produced by a low-energy and eco-friendly microwave-assisted method. Different microwave times (10, 20, 30, and 60 min) and temperatures (120, 140, 160, 180 degrees C) were evaluated. Raman and X-ray diffraction (XRD) data detected anatase as the major crystalline phase. XRD also indicated an increase in the interfacial component as the microwave temperature decreases, resulting in a highly energetic surface and super-adsorptive QDs. TiO2 crystallites presented an average size of 5 to 6.2 nm as calculated from the Scherrer equation and confirmed by TEM micrographs. As a feature of the particle size reduction, the QDs synthesized by 10 min and 120 degrees C presented a large specific surface area (similar to 259 m(2.)g(-1)), higher interfacial component (60%), high adsorptivity, and a fast (similar to 5 min) 100% degradation of RR141, making this a promising photocatalyst techno-commercial material.