Photocatalytic degradation of Methyl Orange by TiO_2/schorl photocatalyst: Kinetics and Thermodynamics

摘要

An active dye, Methyl Orange (MO) was employed as the target pollutant to evaluate the photocatalytic activity of TiO_2/schorl composite and the kinetics and thermodynamics of this process was emphasized in this work. Langmuir-Hinshelwood kinetic model was employed for the kinetic studies and the results revealed that the process of MO photocatalytic discoloration by TiO_2/schorl composite followed one order reaction kinetic equation under different conditions. The reaction rate constant (k) increased with initial MO concentration decreasing. When the catalyst dosage or solution pH increased, k values increased and then decreased. The possible reasons for these phenomena were discussed. Finally, the thermodynamic parameters ΔG, ΔH, ΔS were obtained by the classical Van't Hoff equation.