CdO-supported ZrO₂ heterojunctions: facile synthesis and rapid visible-light oxidation of atrazine herbicide with superb recyclability

Abstract

The advancement in ceramic oxide-based photocatalysis has got much attention recently for environmental issues. Atrazine (AZ) is one of the major used herbicides in agricultural and related industries. This work familiarizes a polymeric-assisted sol-gel preparation of high surface area zirconium oxide (ZrO2) supported with cadmium oxide nanoparticles at minor content (0.5−2.0 wt.%). Exploration of the synthesized heterostructures revealed the enhancement of visible-light absorbance and reduction of bandgap energy to 2.76 eV keeping the same crystalline form and high surface area of 170 m2g‒1. The prepared photocatalysts were used to degrade AZ in water at a concentration of 231.8 µM (50 ppm). The 1.5%-introduced CdO to ZrO2 revealed the best-performed photocatalyst for complete oxidation of AZ within 40 at an optimized dose of 1.6 g L–1. This novel ceramic photocatalyst showed a chemical and structural ability to keep 98.5% of its initial efficiency after five regenerated cycles. The construction of p-n heterojunction between the p-type ZrO2 and the n-type CdO contributed to the comprehensive photocatalytic competence toward the efficient charge separation and photooxidation process.