Variation of the photocatalytic performance of decorated MWCNTs (MWCNTs-ZnO) with pH for photo degradation of methyl orange

Abstract

In this work, we reported the variation of the photo degradation of methyl orange with pH using three kinds of MWCNTs-ZnO hybrids. The obtained results exhibit that the removal efficiency of methyl orange using all applied photocatalysts increases by increasing the irradiation time. Meanwhile, the results show that the augmentation of the MWCNTs content in the synthesized photocatalysts from 0.02 to 0.06 g leads to the increment of the photo decomposition of methyl orange. Also, the photocatalytic activity of studied decorated MWCNTs show that the removal efficiency of methyl orange at acidic condition (pH = 4) is higher than that of neutral (pH = 7) and basic (pH = 10) condition. The photocatalytic activity of all studied decorated MWCNTs can be predicted by proposed models with accuracy up to 98%. The results of Duncan’s multiple range test at 5% level of probability reveal that the variation of pH in three studied levels (4, 7 and 10) provides a reasonable effect on the removal efficiency of pollutant.