Photocatalytic removal of imidacloprid containing frequently applied insecticide in agriculture industry using Co₃O₄ modified MoO₃ composites

Water pollution caused by the frequent utilization of pesticides in the agriculture industry is one of the major environmental concerns that require proper attention. In this context, the photocatalytic removal of pesticides from contaminated water in the presence of metallic oxide photocatalysts is quite in approach. In the present study, Orthorhombic MoO₃ has been modified with varying amount of cobalt oxide through wet impregnation for the removal of imidacloprid and imidacloprid-containing commercially available insecticide. The solid-state absorption response and band gap evaluation of synthesized composites revealed a significant extension of absorption cross-section and absorption edge in the visible region of the light spectrum than pristine MoO₃. The indirect band gap energy varied from ∼2.88 eV (MoO₃) to ∼2.15 eV (10% Co₃O₄-MoO₃). The role of Co₃O₄ in minimizing the photo-excitons’ recombination in MoO₃ was studied using photoluminescence spectroscopy. The orthorhombic shape of MoO₃ was confirmed through X-ray diffraction analysis and scanning electron microscopy. Moreover, the presence of distinct absorption edges and diffraction peaks corresponding to Co₃O₄ and MoO₃ in absorption spectra and XRD patterns, respectively verified the composite nature of 10% Co₃O₄-MoO₃. The photocatalytic study under natural sunlight irradiation showed higher photocatalytic removal (∼98%) of imidacloprid with relatively higher rate by 10% Co₃O₄-MoO₃ composite among all contestants. Furthermore, the photocatalytic removal (∼93%) of commercially applied insecticide, i.e., Greeda was also explored.