Fe-TiO2-SiO2/QCS复合膜催化剂的制备及其甲基橙光降解性能研究

Preparation of Fe-TiO2-SiO2/QCS composite membrane catalyst and its photodegradation performance of methyl orange

在季铵化壳聚糖(QCS)铸膜液中,借助水解反应将Fe-TiO2和Fe2O3量子点负载于多孔SiO2孔结构中,制备Fe-TiO2-SiO2/QCS复合膜催化剂。通过X射线衍射、透射电镜和红外光谱对其进行表征。结果表明:当Ti/Fe(摩尔比)≥10时,形成Fe-TiO2量子点;当Ti/Fe(摩尔比)≤3时,形成Fe2O3量子点。以甲基橙为模型污染物,在λ=365nm的辐射源辐照下,研究Fe-TiO2-SiO2/QCS膜催化剂催化降解甲基橙染料的性能。结果表明:当甲基橙初始浓度C0=10mg/L,pH=2时,Ti/Fe=3的复合膜催化剂对甲基橙溶液的降解率达到最大值(90%),明显高于只含TiO2复合膜催化剂相同条件下光催化降解甲基橙的降解率(60%)。

Fe-TiO2 and Fe2O3 quantum dots were supported in the SiO2 structure by hydrolysis reaction,and then the quaternized chitosan was used as the film matrix.The above materials were introduced into the quaternized chitosan(QCS)casting solution to prepare Fe-TiO2-SiO2/QCS composite membrane catalyst.The catalyst was characterized by XRD,TEM and FT-IR.The results shown that when Ti/Fe(molar ratio)≥10,Fe-TiO2 quantum dots were formed.When Ti/Fe(molar ratio)≤3,additional Fe2O3 quantum dots were formed.The photocatalytic degradation of methyl orange was studied by Fe-TiO2-SiO2/QCS film under ultraviolet lightλ=365nm with methyl orange as a pollutant model.The initial concentration of methyl orange solution and the effect of pH value on the catalytic efficiency of the membrane were investigated.When the initial concentration of methyl orange C0=10mg/L,pH=2,the degradation rate of the Ti/Fe=3 membrane to methyl orange solution reached a maximum of 90%.It was significantly higher than the 60%degradation rate of photocatalytic degradation of methyl orange under the same conditions of TiO2 composite membrane catalyst alone.