Photodegradation of 2-chlorophenol over ZnO/KCC-1: Reaction optimization by response surface methodology

Abstract

Removing 2-chlorophenol (2CP) from water is an imperative task due to its toxicity. Various methods have been introduced for 2CP removal, and photocatalytic degradation is one of the best alternative solutions due to its effectiveness and simple process. This study focused on the potential of ZnO/KCC-1 as an effective photocatalyst for 2CP elimination from aqueous solutions. ZnO/KCC-1 was prepared by impregnating a commercial ZnO precursor into the synthesized KCC-1. The Zn/KCC-1 was characterized using TEM, FESEM, XRD, FTIR, and PL. The TEM and FESEM analyses confirmed the catalyst’s fibrous structure with good ZnO dispersion. The XRD results demonstrated the amorphous silica structure with the presence of ZnO, while the FTIR analysis confirmed the formation of a strong Si-O-Zn bond. The PL analysis revealed a slower recombination rate of electrons and holes during the reaction, thus enhancing the degradation rate efficiently. The analysis via response surface methodology (RSM) over independent variables of initial concentration (X1), catalyst dosage (X2), and pH (X3) revealed that X2 was the most essential variable, while X1 was the least significant variable. The ideal parameter for 2CP degradation was achieved at X1 = 10 mg/L, X2 = 2 g/L, and X3 = 10 with photodegradation efficiency (Y) of 90.62 % (predicted) and 88.93 % (experimental). This research revealed that ZnO/KCC-1 had a great prospect for photocatalytic degradation of 2CP from an aqueous solution.