Highly efficient visible light TiO₂ photocatalyst prepared by sol–gel method at temperatures lower than 300°C

• Published in: Journal of hazardous materials Vol. 192; no. 1; pp. 150 - 159
• Main Authors: Wang, Desong, Xiao, Libin, Luo, Qingzhi, Li, Xueyan, An, Jing, Duan, Yandong
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.08.2011; Elsevier
• Subjects: absorption; Applied sciences; Atmospheric pollution; carbon; Catalysis; Catalytic reactions; Chemical engineering; Chemistry; Crystallography, X-Ray; Exact sciences and technology; Fourier transform infrared spectroscopy; Gels; General and physical chemistry; heat treatment; Hot Temperature; irradiation; Metal Nanoparticles; methyl orange; Microscopy, Electron, Transmission; monitoring; nanoparticles; photocatalyst; Photochemistry; photolysis; photosensitivity; Pollution; Raman spectroscopy; Reactors; reflectance spectroscopy; sol-gel processing; Spectrophotometry, Ultraviolet; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis, Raman; temperature; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Thermogravimetry; Titanium - chemistry; titanium dioxide; transmission electron microscopy; X-ray diffraction; X-ray photoelectron spectroscopy; Heat treatment; Nanoparticle; Sol-gel method; Doping; Ultrafine particle; Visible radiation; Optical thickness; Fourier-transformed infrared spectrometry; Titanium dioxide; Photochemical degradation; Photodegradation; Differential scanning calorimetry; Stability; Pollutant behavior; Photocatalysis; Thermogravimetry; Air quality; X ray diffraction; Carbon self-doping; Ultraviolet radiation; Transmission electron microscopy; Surveillance; Visible light photosensitive groups; Aerosols; Air pollution; Visibility; Kinetics; Titanium oxide; Catalyst; Reflectance
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2011.04.110

Highly efficient visible light TiO₂ photocatalyst was prepared by the sol–gel method at lower temperature (≤300°C), and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), UV–vis diffuse reflectance spectroscopy (UV–vis DRS), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and differential scanning calorimetry-thermogravimetric analysis (DSC–TGA). The effects of the heat treatment temperature and time of the as-prepared TiO₂ on its visible light photocatalytic activity were investigated by monitoring the degradation of methyl orange solution under visible light irradiation (wavelength≥400nm). Results show that the as-prepared TiO₂ nanoparticles possess an anatase phase and mesoporous structure with carbon self-doping and visible photosensitive organic groups. The visible light photocatalytic activity of the as-prepared TiO₂ is greatly higher than those of the commercial TiO₂ (P-25) and other visible photocatalysts reported in literature (such as PPy/TiO₂, P3HT/TiO₂, PANI/TiO₂, N–TiO₂ and Fe³⁺–TiO₂) and its photocatalytic stability is excellent. The reasons for improving the visible light photocatalytic activity of the as-prepared TiO₂ can be explained by carbon self-doping and a large amount of visible photosensitive groups existing in the as-prepared TiO₂. The apparent optical thickness (τₐₚₚ), local volumetric rate of photo absorption (LVRPA) and kinetic constant (kT) of the photodegradation system were calculated.