One-pot electro-synthesis of ZrO2–ZnO/HY nanocomposite for photocatalytic decolorization of various dye-contaminants

Abstract

A highly photoreactive electrogenerated catalyst (EGZrO2–EGZnO/HY) was prepared by a facile one-pot electrochemical method. The restructuring of the aluminosilicate protonated Y zeolite (HY zeolite) framework presumably occurred during electrolysis via dealumination accompanied by the insertion of Zr and Zn ions resulting from anodic dissolution to form a new active species, Si coordinated with Zr and Zn in the HY framework. The photoactivity of the photocatalyst was examined by photodecolorization of methylene blue (MB) under varying pH, catalyst dosage, and initial concentrations of MB. An amount of 0.60gL−11wt.% EGZrO2–1wt.% EGZnO/HY was found to be the optimum dosage for 10mgL−1 MB, which gave almost complete photodecolorization of methylene blue after 1h under visible light at pH11 and room temperature. The photocatalytic reaction followed pseudo first-order kinetics which were rationalized in terms of the Langmuir–Hinshelwood model, and provided nearly complete mineralization. After five cycling runs, the catalyst was still stable and showed no leaching effect. High decolorization percentage (>80%) of other dyes such as malachite green (MG), Congo red (CR), and methyl orange (MO) were also obtained.