纳米MnO2/羧甲基纤维素复合膜制备及光催化降解罗丹明B性能研究

Preparation of nano-MnO2/CMC composite film and its photocatalytic performance for degrading rhodamine B

采用溶胶-凝胶法结合流延包覆方法制备纳米二氧化锰(MnO2)/羧甲基纤维素(CMC)复合膜(纳米MnO2/CMC复合膜),并对样品进行测试,复合膜催化剂呈MnO2颗粒状自然堆积,颗粒间无团聚,表面光滑,纳米直径20nm±5nm,是高量子活性纳米MnO2,MnO2的含量为28.6%(wt,质量分数)。纳米MnO2/CMC复合膜具有聚合物CMC的强溶胀吸附性和纳米MnO2光催化活性,对催化降解罗丹明B印染废水效果明显。研究结果表明,在温度为20℃,pH=4.0,罗丹明B溶液浓度为100mg/L,复合膜用量为0.75g/L条件下,罗丹明B溶液的降解率达86.6%,吸附容量为8.09mg/g,处理后废水中的罗丹明B含量低于0.1mg/L,达到染料废水排入城镇下水道水质标准。

Nano-MnO2/CMC composite film was prepared by sol-gel combined with cast coating method.The results showed that the composite catalysts grown naturally in the form of particles and there was no agglomeration among the particles.With a smooth surface and a nanometer diameter of 20nm±5nm,it was a highly quantum active nano-MnO2with the MnO2content of 28.6%(wt,mass fraction).The composite films combined the strong swelling and adsorbability of the polymer by water and the high photocatalytic activity of nanometer MnO2,and the films presented obvious photocatalytic efficiency for degrading rhodamine B wastewater.The concentration of wastewater and catalyst dosage were exhibited on the degradation rate of rhodamine B solution and the equilibrium adsorption capacity.The results shown that when the temperature was 20℃,pH=4.0,the concentration of rhodamine B solution was 100mg/L and the amount of composite film was 0.75g/L,the degradation rate of rhodamine B solution can be 86.6%with the adsorption capacity of 8.09mg/g.Finally,the discharge of rhodamine B in the treated wastewater was lower than 0.1mg/L,which met the water quality standard for sewage discharge into urban sewers.