Optimization and modeling of preparation conditions of TiO2 nanoparticles coated on hollow glass microspheres using response surface methodology

• Hollow glass microspheres (HGMs) were employed as support.
• Response surface methodology was used to optimize synthesis conditions of TiO2–HGMs.
• TiO2 film was coated on the HGMs by sol–gel method.
• The structure of TiO2–HGMs prepared was core–shell.
• Methane orange was decomposed by photocatalytic oxidation assisted with TiO2–HGMs.

Response surface methodology was used to find and optimize the effect of the variables on the preparation, morphology and catalytic activity of nano-crystalline TiO2 thin films coated on hollow glass microspheres (HGMs) by sol–gel method. Three experimental parameters were chosen as independent variables: the calcination temperature, the amount of titanium butoxide and template F127. Morphology analysis showed that structure of TiO2–HGMs prepared was core shell, and the surface of HGMs was coated by TiO2 thin films with an average layer thickness of 728 ± 12 nm. A quadratic model was established as a functional relationship between three independent variables and the degradation efficiency of methyl orange (MO). The results of model fitting and statistical analysis demonstrated that the amount of titanium butoxide and F127 played a key role in discoloration for MO. The optimum conditions for maximum MO degradation efficiency (98.6%) were titanium butoxide of 18.64 g, F127 of 3.12 g and calcination temperature of 501.89 °C.