Relationship between TiO₂ particle size and reactor diameter in solar photoreactors efficiency

The optimal experimental conditions for photocatalysis are determined for a cylindrical non-concentrating photoreactor using a TiO₂ catalyst suspension using technical grade Imidacloprid (50 mg/l) as a model compound, two different particle sizes (obtained by several preparation protocols) of the same TiO₂ (Degussa P25) and three concentrations (50, 200 and 500 mg/l) to test the optimal TiO₂ concentration. Three inner diameters of reactor were also tested for the best dimension for each catalyst concentration. These experiments have demonstrated that the optimum conditions tested were 2.55 cm inner diameter, 200 mg TiO₂/l and 300 nm mean particle size. At the same time, the influence of the relationships between the three parameters studied (catalyst concentration, particle size and reactor diameter) is discussed.