Effect of sol composition on the properties of TiO2 powders obtained by the sol-gel method

Abstract The influence of sol composition and water content, selected alcohols, and the presence of deflocculant and acid on the photocatalytic properties of TiO2 powders obtained by the sol-gel method was investigated. In order to prepare the sol, titanium IV butoxide, three different alcohols, diethanolamine, deionized water, and HCl were used. All samples were annealed under constant conditions at a temperature of 500 °C for 90 min. The XRD results revealed that a mixture of anatase and brookite could be obtained in the as-synthesized powders obtained from the sols with the addition of HCl. Powders including only anatase phase could be obtained from the annealed sols without the addition of HCl. The photocatalytic performance of the samples with anatase and a mixture of anatase and brookite was thoroughly investigated in the degradation of bromophenol blue solutions. TiO2 powders containing two polymorphs exhibited superior photocatalytic properties compared to single-phase powders with anatase.