INFLUENCE OF MICROWAVE/ULTRASOUND IRRADIATION ON THE SOL-GEL SYNTHESIS OF TITANIUM DIOXIDE NANOPARTICLES FOR APPLICATION IN PHOTOCATALYSIS

TiO2 nanoparticles were synthesized by the sol-gel method in order to optimize their textural and morphological properties for its application in photocatalysis. These materials were obtained by changing the hydrotreatment in the crystallization stage. Each sample was prepared according to the case with microwave irradiation(MO), ultrasound(US), combined mode(microwave-ultrasound(MC)) or conventional method(reflux), note that MC has not been reported. It was found that the optical (band gap(Eg)), textural and morphological properties depended on the type of irradiation during the crystallization stage. The SEM (scanning electron microscopy) micrograms showed two morphologies one monolithic and the other of aggregates of lobular particles. In the case of MO and reflux the morphology is composed of aggregates of lobular particles for US in monolithic form and finally for the MC, the morphology was heavily influenced by the US effect. For the photocatalysis evaluation, it was observed in the analyzed samples that a higher percentage of anatase phase, surface area, volume and pore size at the same value of Eg, there is an increment of photodegradation of methyl orange. As a result, the best material obtained for photodegradation was TiO2 synthesized by the combined method(MC).