Construction of sandwich like RGO/BiVO4/ZSM-5 hybrid heterostructure for the enhanced photocatalytic removal of p-chlorophenol

Abstract

Development of effective photocatalytic systems are of crucial importance as these materials tend to be visible light active and the staggered positioning of their band edges combat charge carrier recombination. This work reports the effective construction of RGO/BiVO4/ZSM-5 NCs via ultrasonication assisted hydrothermal method for effective removal of organic compounds. Tuning of morphology such as polygonal ZSM-5 provides widespread exposure of reactive sites for photo-oxidation process, thereby increasing the overall efficiency. The photocatalytic experiment was conducted in different operational parameters including varying nanomaterial concentration, p-chlorophenol (PCP) concentration, pH and ions. The results exhibited that at 20 mg/L NCs with 20 mg/L PCP concentration at pH 6 had the highest photocatalytic efficiency (96% in 300 min) under visible light irradiation. The photodegradation process followed pseudo-first order kinetic and the dominant reactive species were found to be •OH and O2•−. Moreover, the nanomaterial exhibited excellent photostability and reusability, which was confirmed after six consecutive cycle tests. In addition, a possible photodegradation pathway was proposed with the intermediates obtained from GCMS analysis. These degraded intermediates have also been evaluated for its chronic and acute toxicity with ECOSAR program. The obtained results improve the current understanding of developing novel photocatalytic systems for effective removal of hazardous pharmaceutically active pollutants.