Photocatalytic Glycerol Conversion and Rhodamine B Degradation: Influence of TiO2 Properties by Transformation of Anatase and Rutile Phases

TiO2 was synthesized by precipitation method at different calcination temperatures and characterized. Materials exhibiting diverse surface, structural and surface properties were obtained and evaluated in the photodegradation of rhodamine B (RhB) dye, and the photocatalytic conversion of glycerol. The increase in the calcination temperature caused a decrease in the surface area (109.0, 69.0, 9.0, and 5.0 m(2)/g for TiO2-350, TiO2-550, TiO2-750, and TiO2-950, respectively) and a transformation of anatase to rutile phase. For the photodegradation of RhB, the photocatalytic efficiency was 58.6, 62.8, 31.7, and 16.5% for TiO2-350, TiO2-550, TiO2-750, and TiO2-950, respectively. The n-deethylation was improved using TiO2-350 (higher surface area) and chromophore cleavage appeared to improve when mixed anatase-rutile crystal-line phases of TiO2 were identified. For the photocatalytic conversion of glycerol, the surface area was a determining factor in increasing the conversion with photocatalytic efficiency was 20.5, 15.6, 10.8, and 6.6% for TiO2-350, TiO2-550, TiO2-750, and TiO2-950, respectively, but the TiO2 phase transformation proved to be important for the selectivity and yield of the identified products. The results obtained emphasize the vital role of investigations of photocatalysts for advanced studies on formation of by-products from the n-deethylation of rhodamine B. Furthermore, no similar studies using TiO2 synthesized by the precipitation method for photocatalytic conversion of glycerol were related, even though this is an important innovation for obtaining products of industrial interest under mild reaction conditions.