中心组合设计优化S-Cr-TiO_2催化剂光降解工艺条件

Optimization of Technology Condition for Photodegradation on S-Cr-TiO_2 Catalyst by Central Composite Design

在确定的温度和光照条件下,采用中心组合设计法研究了固相反应法合成的硫与铬共掺杂二氧化钛(S-Cr-TiO)2光催化剂与水溶苯胺蓝(ANB)可见光降解过程中的三个作用因子:催化剂的浓度、水溶苯胺蓝水溶液的pH值及其初始浓度之间的相互作用关系,得到了影响因子与降解速率之间的回归方程及因素之间相互作用的响应面图。结果表明,S-Cr-TiO2光催化剂对水溶苯胺蓝的可见光降解过程遵循一级反应动力学规律。当催化剂浓度为2.05g/L,水溶苯胺蓝的浓度为42.57mg/L、pH=6.63时,光降解速率常数为0.01432 min-1,比未优化工艺条件时所得光降解反应速率常数0.01348min-1提高了6.2%。中心组合设计对筛选光降解工艺条件,提高光降解效率是十分有效的。

At certain temperature and illumination conditions,3 components such as consumption concentration of catalyst,pH value and initial concentration of water soluble aniline blue（ANB）that affecting photodegradation rate of ANB on S and Cr co-doped TiO2 photocatalyst（S-Cr-TiO2）prepared by solid state reaction route were investigated by using central composite design.And the regression equation and response surface figure from interaction of the three factors were presented.Results showed that the rule of pseudo-first-order reaction was found in the visible light degradation of ANB on the S-Cr-TiO2 nanomaterial,and the catalyst consumption of 2.05 g/L,initial concentration of ANB 42.57 mg/L and pH value of 6.63 were optimum conditions,the photodegradation rate constant of 0.014 32 min^-1 was obtained,6.2% more than that the photodegradation rate constant of 0.013 48 min^-1 by un-optimization conditions experiment design.The central composite experiment is proved to be effective in selecting reaction conditions and then improving visible light degradation rate constant.