交联壳聚糖-CdS颗粒可见光催化脱色甲基橙研究

利用壳聚糖对金属离子的配位络合作用和吸附性能,模拟生物矿化仿生制备交联壳聚糖/CdS复合粒子。以甲基橙为处理对象,氙灯模拟可见光,研究了该复合材料对甲基橙的降解脱色性能。用Langmuir-Hinshelwood方程从动力学的角度,考察了不同催化剂浓度、甲基橙的初始浓度、反应体系的pH值、外加无机阴离子等对甲基橙降解脱色的影响。结果表明,该复合材料的吸附性能和光催化活性产生的协同作用能较有效促进甲基橙染料的脱色,在低质量浓度条件下可见光催化过程为假一级反应。光催化剂的最佳用量为1.5g/L,甲基橙降解的最佳pH为4.0。Cl-和Br-均对MO的光催化脱色起抑制作用,而NO3-的添加明显促进MO的光催化速率。

Biominetic Methods of Crosslinked Chitosan-CdS Composite Particles and Photocatalytic Decolorization Dynamics of Methyl Orange by Visible Light

Aimed at adsorption ability and complexation with metal ions of chitosan,crosslinked chitosan/CdS composite particles were prepared by simulating bio-mineralization process. Process of photocatalytic decolorization of methyl orange on crosslinked chitosan/CdS composite particles was studied using Xenon as simulated visible light. Based on Langmuir-Hinshelwood kinetic equation,the effect of catalyst concentration,dye initial concentration,pH and kinds of anions on methyl orange decolorization was investigated. Results showed that decolorization of methyl orange enhanced significantly by synergetic effect of adsorption and photocatalytic activity. Photocatalytic decolorization followed pseudo-first order kinetics under low dye concentration. The optimal chitosan/CdS catalyst amount was 1.5g/L and optimal pH value was 4.0. The addition of Cl and Br had an inhibitory effect on decolorization of methyl orange,while the addition of NO3-had an accelerative effect on decolorization of methyl orange.