Highly photoactive supported TiO2 prepared by thermal hydrolysis of TiOSO4: Optimisation of the method and comparison with other synthetic routes

Supported TiO2 on sintered borosilicate glass (100–160 μm pore size) was prepared by a synthetic route based on the thermal hydrolysis of titanium oxysulfate (TiOSO4). An optimisation of the preparation method to obtain more stable and photoactive supported TiO2 was achieved by the control of the different preparation parameters influencing the final properties of the supported TiO2. A comparative study with other coatings prepared by sol–gel or hydrolysis methods on sintered glass was performed. The examination of the coatings by scanning electron microscopy (SEM) showed a notably different morphology depending on the preparation method. The photocatalytic activity of the different supported TiO2 materials was tested for the photooxidation of glucose in water. The optimised supported TiO2 prepared by thermal hydrolysis of TiOSO4 exhibited a considerably higher photoactivity than the other studied coatings, reaching values of the photonic efficiencies as high as 7%. The stability and lifetime of the most active supported TiO2 was tested following the evolution of its photocatalytic activity for more than 5 months of continuous operation. No important decrease of the efficiency could be observed during this time.