CNT/CdS/壳聚糖-H_2O_2可见光光催化甲基橙脱色研究

Photocatalytic Decolorization of Methyl Orange by CNT/CdS/Chitosan-H_2O_2 System under Visible Light Irradiation

利用共沉淀法制备了具有可见光响应的CNT/CdS复合薄膜光催化材料。以氙灯模拟日光光源,并以双氧水辅助氧化,对甲基橙进行光催化降解,探讨了不同工艺、催化剂用量、双氧水用量、甲基橙初始浓度、溶液pH值、无机阴离子对光催化降解脱色的影响以及催化剂的重复使用性。实验结果表明:双氧水对CNT/CdS光催化甲基橙脱色产生协同作用,其次,光照是必不可少的因素。当甲基橙起始浓度为15 mg/L,CNT/CdS用量为0.7 g/L,双氧水用量为3.90 mmol/L,pH值为6.4时,光照100 min后甲基橙可完全脱色。酸性媒介比碱性媒介更有利于甲基橙染料的光解脱色。催化剂重复使用5次后,反应100min后脱色率仍高达91.55%。处理前后的UV-Vis谱图分析表明甲基橙在H2O2/催化剂光降解处理中脱色是染料发生光降解作用所致。

CNT/CdS composite films for response to visible light were prepared by co-precipitation process.The experiment of photocatalytic decolorization of methyl orange dye assisted by hydrogen peroxide was conducted under Xenon lamp simulated sunlight irradiation.Effects of different process,catalyst amount,H2O2 dosage,initial dye concentration,pH,different anions and reusability of catalyst on photocatalytic decolorization of methyl orange were studied.Results showed that H2O2 cooperated with CNT/CdS photocatalytic decolorized methyl orange effectively and light irradiation was the essential condition.Under the conditions of initial methyl orange concentration 15 mg/L,CNT/CdS catalysts amount of 0.7 g/L,H2O2 dosage of 3.90 mmol/L and pH 6.4,methyl orange can be decolorized totally after 100min irradiation.Methyl orange could be more efficiently decolorized in an acid media than basic media.After the catalyst was reused for 5 times,dye decolorization rate was still up to 91.55% within 100 min irradiation.UV-Vis spectra indicated that the decolorization of methyl orange by H2O2 /catalyst photocatalysis treatment was due to the degradation of the dye.