Photocatalytic degradation kinetics of methyl orange in TiO2-SiO2-NiFe2O4 aqueous suspensions

Photocatalytic degradation of methyl orange by TiO2-SiO2-NiFe2O4 suspensions was investigated. Adsorption studies revealed photocatalytic degradation occurred mainly on the surface of the TiO2-SiO2-NiFe2O4. The disappearance of the compound followed the zero-order kinetics according to the Langmuir-Hinshelwood model and the rate constant was 0.0035 mg L-1 min(-1). The rate constant depended on the amount of photocatalyst, initial pH, and the presence of additional scavengers. (OH)-O-aEuro cent radicals and h(+) had important roles in the photocatalytic degradation of methyl orange by TiO2-SiO2-NiFe2O4.