Photocatalytic removal of methylene blue dye from aqueous solution via F-TiO2 dispersed on layered double oxide

• Successful synthesis of a novel F-TiO 2 /LDO heterojunction photoelectrocatalyst. • It was found that OH• played the main role in the MB degradation process. • Mechanism of MB degradation and charge transfer process was proposed. • 4. High stability of the photocatalyst F-TiO 2 /LDO (500°C) Photoelectrocatalytic treatment of pollutants combining advanced oxidation processes can effectively solve the wastewater dilemma and maintain green and sustainable development. The exploration of titanium oxide-based (TiO 2 ) and layered double oxide-based (LDO) nanocomposites has grown considerably with recent research focusing on improving and expanding their scope of application for the creation of sustainable matrices. Both oxide-based nanocomposites exhibit exceptional properties in addition to possessing high responsiveness to different types of light and distinctive reactive interfaces, which provide numerous active sites for the reduction, oxidation, and adsorption of contaminants. Heterojunction structures are gaining popularity due to their ability to bring and combine critical properties to materials, which is important in materials science. In this study, an F-TiO 2 -based hybrid nanocomposite was synthesized by dispersing F-TiO 2 on ZnAl-LDO via a simple hydrothermal technique to fabricate an F-TiO 2 /LDO composite material with excellent electrochemical properties and characteristic photoresponse. The results of optical and photoelectric analyses demonstrate that the dispersion of F-TIO 2 on LDO characteristically changes the F-TIO 2 /LDO light absorption capacity (maximum between 380 and 430 nm and 690 to 800 nm UV-visible). This also leads to a significant improvement in the spatial separation and transfer efficiency of photogenerated electrons and holes. The electrochemical performance test results indicate that constructing a suitable combination of F-TiO on and LDO resulted in effective acceleration of photogenerated electron-hole pair separation and transfer, improvement of catalytic oxidation activity and charge carrier separation efficiency. In here, photoelectrocatalysis appears to be the main route of MB treatment, while •OH is the main reactive species during the MB degradation process. The kinetic mechanism of the degradation process fits to the Langmuir-Hinshelwood model (R 2 =0.99281) describing the kinetics of heterogeneous catalytic processes. As a sign of its exceptional stability, even after five cycles of MB degradation by F-TiO 2 /LDO, the as-prepared composite material still retains 92.5% of its initial degradation efficiency. It could then result from the formation of an F-TiO 2 and LDO heterojunction area resulting in a synergistic photoelectrocatalysis effect.