Visible-light-driven photocatalytic degradation of ofloxacin (OFL) antibiotic and Rhodamine B (RhB) dye by solvothermally grown ZnO/Bi2MoO6 heterojunction

The 3D hierarchical ZnO/Bi2MoO6 heterojunctions were fabricated via an in-situ solvothermal method. To the best of our knowledge, this is the first report based on synthesis of ZnO/Bi2MoO6 heterojunction by decoration of ZnO nanoparticles on the surface of the flower-like Bi2MoO6 superstructures. The prepared ZnO/Bi2MoO6 heterojunctions exhibited the characteristic diffraction peaks of ZnO and Bi2MoO6 with the band gap energy of 3.25 eV and 2.76 eV, respectively. The PL intensity of the 10 wt% ZnO/Bi2MoO6 heterojunction (denoted as 0.10Zn-Bi) is much lower than that of the bare Bi2MoO6, indicating much more effective separation of photo-generated electrons and holes at the interface which in turn results in greater expected photocatalytic performance. The 0.10Zn-Bi heterojunction showed the highest efficiency of 100% and 92% toward photodegradation of OFL antibiotic and RhB dye, respectively, due to the greatest surface area and the lowest electron-hole recombination rate. The photodegradation of the pollutants followed pseudo-first order kinetics with a very high rate constant of 0.0196 min(-1). The chemical structure of photocatalyst remained stable after five cycles of use. The photogenerated electron (e(-)) and hole (h(+)) are two major reactive species involved in photodegradation of both OFL antibiotic and RhB dye. The present work demonstrates a very high potential of the 3D hierarchical ZnO/Bi2MoO6 heterojunctions for environmental remediation. (C) 2020 Elsevier Inc. All rights reserved.

Automated summary

Hierarchical 3D ZnO/Bi2MoO6 heterojunctions were successfully fabricated via an in-situ solvothermal method, showing characteristic diffraction peaks corresponding to ZnO and Bi2MoO6 with band gap energies of 3.25 eV and 2.76 eV, respectively. The heterojunction exhibited enhanced photocatalytic performance, achieving 100% and 92% efficiency in degrading OFL antibiotic and RhB dye, respectively, due to improved electron-hole separation and larger surface area.