Modified gelcasting of microwave assisted synthesized sulfur-doped anatase for photocatalytic degradation of organic compounds

Sulfur-doped anatase nanoparticles were synthesized using titanium isopropoxide and thiourea, reactions were done through a microwave assisted hydrothermal method to control the morphology, crystallinity and the dimensions. Pure anatase was also obtained as a reference material for photocatalytic characterization. All synthesis reactions were carried out at 215 degrees C, using a potency of 600W during 60 min. Crystalline phases were identified by XRD and by HRTEM the crystal structure was studied, and the dimensions of nanocrystal were determined. The images recorded were analyzed with a Digital Micrograph software. Subsequently, the synthesized anatase was used in order to obtain ceramics with controlled porosity through the modified gelcasting process. This process was performed in order to reduce the photocatalyst loss when organic compound degradation reactions were carried out. The anatase was mixed with polymers, dispersants and solvents to produce a reticulated gel which made the anatase easy to be molded and consequently, ceramic plates were formed. The ceramic porosity was observed with a SEM and their photocatalytic activities were evaluated by photodegradation reactions of methyl red dye in water solution. All these reactions lasted 3 h and samples were collected at different times during the reaction. Color removal was evaluated with UV-vis measurements following the color disappearing at 434 nm wavelength. Significant differences in photocatalytic properties were observed between doped and pure anatase despite the low concentration of sulfur (0.1% weight.) (C) 2016 Elsevier B.V. All rights reserved.