壳聚糖-CdS复合纳米粒子对甲基橙的光催化降解作用

用反相微乳液法制备了壳聚糖-CdS复合纳米粒子,并考察了复合纳米粒子用量、光照条件和溶液pH值等因素对光催化降解甲基橙的影响.结果表明:在100 mL质量浓度为20 mg/L的甲基橙溶液中加入0.30 g复合纳米粒子,可以达到较好的光催化降解效果;甲基橙在光催化降解过程中最大吸收波长464 nm处的吸收峰迅速减弱,并最终消失,且在258 nm和455 nm处出现了新的吸收峰,说明甲基橙发生了降解;溶液pH值对光催化降解甲基橙有一定的影响,在弱酸性条件下降解效率较高;复合纳米粒子比普通CdS降解效率高,2 min时高出50%,400 min时高出21.3%.初步提出了复合纳米粒子光催化降解机理,复合纳米粒子的吸附作用是光催化降解作用的前置步骤.

Photocatalytic degradation of methyl orange by chitosan-supported CdS nanoparticles

To study the effects of some factors such as the amount of composite nanoparticles,different lights and pH values of the solution,et al on the photocatalytic degradation of methyl orange,chitosan-supported CdS nanoparticles were prepared by reverse microemulsion reaction.The results showed that the degradation efficiency was excellent when the concentration was 20 mg/L in 100 mL solution containing 0.30 g composite nanoparticles.The absorption peak became weak rapidly and disappeared finally at maximum absorption wavelength of 464 nm,and the new absorption peaks appeared at 258 nm and 455 nm,which showed that methyl orange degradation occurred.Elimination of methl orange was higher in weak acid conditions.The photocatalytic degradation efficiency was increased by 50% and 21.3% respectively at 2 min and 400 min compared with common CdS.The photocatalytic degradation mechanism of composite nanoparticles was put forward preliminarily,in which the adsorption of composite nanoparticles was the prepositive step.