Hybridising nitrogen doped titania with kaolinite: A feasible catalyst for a semi-continuous photo-degradation reactor system

The application of TiO₂ catalyst for an industrial water treatment process is still limited due to its poor reusability, low oxidation efficiency and UV light use. Taking these challenges as the objective of this study, we integrated particle impregnation with nitrogen-doping methods to hybrid nitrogen doped TiO₂ nanoparticles with kaolinite (NTK) as the photocatalyst for water treatment. SEM/TEM, XPS and XRD results revealed that the doped nitrogen in the NTK particle inclined toward interstitial, and the TiO₂ nanocrystals were hybridised into the layered kaolinite minerals. Kaolinite was found to be an excellent TiO₂ nanocatalyst supporter, providing promising adsorption transitions to not only sensitise TiO₂ nanocrystals, but also enhance their photocatalytic oxidation capacity and recoverability. Kinetic studies showed that the NTK catalysts demonstrated a superior interfacial oxidation and photocatalytic degradation ability under visible light irradiation. Importantly, the NTK catalysts could be easily recovered for reuse with stable photo-degradation performance in a semi-continuous photoreactor process. The high degradation capacity, reusability and visible light accessibility of the NTK catalysts make the NTK-catalysed technology promising for industrial applications.