Fabrication of ZnO/Polypyrrole/Carbon Nanotube Nanocomposite and its Application for Removal of 4-Chlorophenol from Wastewater

Abstract

The present work demonstrates a facile solution method for the preparation of ZnO/polypyrrole/carbon nanotube (ZnO/PPy/CNTs) nanocomposite as an effective photocatalyst for the degradation of 4-Chlorophenol (4-CP) from industrial wastewater under irradiation with UV and simulated sunlight. Structural and morphological characterizations using XRD and SEM illustrated the successful formation of ZnO/PPy/CNTs nanocomposite. EIS analysis showed that ZnO/PPy/CNTs with the low charge transfer resistance, can improve the interfacial photogeneraed carrier transfer rate. Optical studies of samples using UV-vis absorption spectra indicated that the optical band gaps of ZnO, ZnO/PPy and ZnO/PPy/CNTs were estimated ~3.39, 3.30 and 3.17 eV, respectively, and the values of the optical band gap of ZnO decreased slightly as PPy and CNTs were added to the ZnO structure. The complete degradation of 100 ml of 6mg/l 4-CP in water for ZnO, ZnO/PPy and ZnO/PPy/CNTs was obtained after 160, 140 and 120 minutes of exposure to UV light, and after 150, 120 and 100 minutes of exposure to simulated sunlight, respectively. The results showed that ZnO/PPy/CNTs exhibited the effective performance for photodegradation of 4-CP under simulated sunlight because of positive synergistic effect of PPy and CNTs on the light harvesting ability of ZnO. Study of the capability of the ZnO/PPy/CNTs for degradation of 4-CP in the prepared real sample of textile wastewater showed the proposed photocatalyst can effectively be used for the degradation of 4-CP from industrial wastewater.