[Photoelectrocatalytic degradation kinetics of malachite green by Pr-N co-doped TiO2 photocatalyst].

Malachite green oxidation degradation was kinetically investigated in a photoelectrocatalytic reactor, using Pr-N co-doped TiO2 photocatalyst as the electrode which was prepared by a sol-gel method. The result shows that the initial concentration, pH, voltage and temperature had a significant impact on the oxidation rate. The kinetic equation for malachite green oxidation under the conditions of 10-30 mg x L(-1) of initial concentration, 3-8 of pH, 1-5 V of voltage, 298-338 K of temperature could be described using the first order kinetics, which was fitted well with the experimental data. The lower activation energy of 11.99 kJ x mol(-1) shows the reaction can be initiated easily; The reaction order of pH (1.634 7) is higher than that of voltage (0.850 2) and initial concentration (0.123 8), which indicates that the oxidation rate can be controlled efficiently through adjusted pH.