Enhanced effect of combination of new hybrid TiO2 phase and phosphorus dopant on the physicochemical properties and UV/Visible light photocatalytic activity

Highlights: • New hybrid P-TiO₂ phase mixture: Magneli (Ti₁₅O₂₉) phase, brookite and anatase. • New hybrid P-TiO₂ phase mixture and P dopant increases Ti³⁺ ions, oxygen defects. • P dopant leads to formation of Ti-O-P bond and decreases the band gap value. • P-TiO₂ phase have lower degree of crystallinity compared to the non-doped. • New hybrid mixture and P dopant increase the ethylene and aspirin oxidation. The presence of triple phase TiO₂ new mixture (Magneli of higher order homologous series, brookite and anatase) containing P dopant ensures positive changes in the structure, in the phase composition and in the chemical composition. These changes explained the reasons for the enhanced UV/Vis photocatalytic efficiency towards oxidative degradation of ethylene and acetylsalycylic acid. The samples were characterized by a set of methods: Raman spectroscopy, Scanning Electron Microscopy (SEM), Diffuse-Reflectance Spectroscopy (DRS), Differential Thermal Analysis (DTA-TG), X-ray Photolelectron Spectroscopy (XPS), Transmission Electron Microscopy and High-Resolution Transmission Electron Microscopy (TEM/HRTEM), Electron Paramagnetic resonance (EPR) and X-ray Diffraction (XRD) analyses. The combination of the optimal set of values of Ti³⁺, oxygen radicals and vacancies, Ti-O-P bonds, narrower band gap is responsible for the higher quantum yield due to the increased number of charge carriers, while the unique phase mixture prevents the recombination of charge carriers. These factors guarantee enhanced rate of the photocatalytic reaction, and extended response to the visible light region.