Preparation of ternary reduced graphene oxide/BiOBr/TiO2 nanotube arrays for photoelectrocatalytic degradation of p-chloronitrobenzene under visible light irradiation

Abstract

The fast recombination of photogenerated charges, low utilization of visible light and difficult recyclability of photocatalysts limit the practical application of photocatalysis technology. Therefore, ternary reduced graphene oxide/BiOBr/TiO2 nanotube arrays (GB/TNAs) photoelectrodes were prepared for the photoelectrocatalytic (PEC) degradation of p-chloronitrobenzene (p-CNB) under visible light irradiation. The internal interaction among different semiconductors demonstrated that the successful fabrication of ternary heterojunction. The photoelectrochemical properties showed that GB/TNAs exhibited higher visible-light absorption property and lower charges recombination than bare TNAs. The p-CNB degradation rate by GB/TNAs reached 0.0055 min−1, which was 3.93 times than that by TNAs (0.0014 min−1). The GB/TNAs effectively solved the recovery of powdered catalysts, and had excellent PEC stability for p-CNB. The coexistence of dissolved anions and humic acid could decline the p-CNB degradation owing to the competition for active sites or behave as the active radical scavengers. The radical quenching experiments and electron spin resonance spectra revealed that the hydroxyl radical and photogenerated holes were the main active species responsible for the degradation, dechlorination and mineralization of p-CNB. The as-prepared GB/TNAs photoelectrodes display a great potential for the degradation of emerging organic contaminants in wastewater.