Pr-N共掺杂TiO_2光电催化降解孔雀石绿动力学

Photoelectrocatalytic Degradation Kinetics of Malachite Green by Pr-N Co-doped TiO_2 Photocatalyst

以溶胶-凝胶法制备的Pr-N共掺杂TiO2催化剂为电极,在光电催化反应器中,研究了光电催化降解孔雀石绿的动力学过程.结果表明,孔雀石绿氧化降解速率与溶液的初始浓度、pH、外加电压及反应的温度有关,在初始浓度为10～30 mg.L-1、pH为3～8、电压1～5 V、温度为298～338 K的实验范围内,反应的氧化降解符合一级反应动力学模型且模型值与实验值吻合良好.模型中反应的初始反应活化能Ea为11.99 kJ.mol-1,说明反应较易进行;pH的反应级数1.634 7,远远高于电压的级数0.850 2及初始浓度的级数0.123 8,表明通过控制pH可有效地提高光电催化的氧化降解速率.

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·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·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.