A review on the visible light active titanium dioxide photocatalysts for environmental applications

• Published in: Applied catalysis. B, Environmental Vol. 125; pp. 331 - 349
• Main Authors: Pelaez, Miguel, Nolan, Nicholas T., Pillai, Suresh C., Seery, Michael K., Falaras, Polycarpos, Kontos, Athanassios G., Dunlop, Patrick S.M., Hamilton, Jeremy W.J., Byrne, J.Anthony, O'Shea, Kevin, Entezari, Mohammad H., Dionysiou, Dionysios D.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 21.08.2012; Elsevier
• Subjects: Air purification; Anatase; Bacteria; Catalysis; Chemistry; Cyanotoxins; Disinfection; Doping; EDCs; Emerging pollutants; Environmental application; Exact sciences and technology; General and physical chemistry; Metal doping; Nanomaterials; Non-metal doping; N–TiO2; Photocatalysis; Photocatalytic; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics); Reactive oxygen species; Remediation; Rutile; Semiconductor materials; Semiconductors; Solar; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; TiO2; Titanium dioxide; Treatment; Visible; Water; Water; N–TiO2; Reactive oxygen species; Solar; Anatase; Rutile; Photocatalysis; Environmental application; Cyanotoxins; Disinfection; Metal doping; Non-metal doping; EDCs; Photocatalytic; Treatment; Air purification; Visible; Emerging pollutants; TiO2; Photoelectrochemistry; Water treatment; Binary compound; Dyes; Hydrogen; Doping; Review; Potential; Degradation; Energy; TiO; Structure; Oxygen; Electronic properties; Purification; Semiconductor materials; Transition element compounds; Pesticides; Electrochemical cell; Air; Heterogeneous catalysis; Pollutant; Light absorption; N-TiO; Titanium oxide; Contaminant; Environmental protection
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2012.05.036

[Display omitted] ► VLA-TiO2 include non metal, metal doping, dye sensitized and coupling semiconductors. ► Physicochemical/photoelectrochemical methods to deduce VLA-TiO2 reaction mechanisms. ► Examination of VLA-TiO2 for water treatment, disinfection and air purification. Fujishima and Honda (1972) demonstrated the potential of titanium dioxide (TiO2) semiconductor materials to split water into hydrogen and oxygen in a photo-electrochemical cell. Their work triggered the development of semiconductor photocatalysis for a wide range of environmental and energy applications. One of the most significant scientific and commercial advances to date has been the development of visible light active (VLA) TiO2 photocatalytic materials. In this review, a background on TiO2 structure, properties and electronic properties in photocatalysis is presented. The development of different strategies to modify TiO2 for the utilization of visible light, including non metal and/or metal doping, dye sensitization and coupling semiconductors are discussed. Emphasis is given to the origin of visible light absorption and the reactive oxygen species generated, deduced by physicochemical and photoelectrochemical methods. Various applications of VLA TiO2, in terms of environmental remediation and in particular water treatment, disinfection and air purification, are illustrated. Comprehensive studies on the photocatalytic degradation of contaminants of emerging concern, including endocrine disrupting compounds, pharmaceuticals, pesticides, cyanotoxins and volatile organic compounds, with VLA TiO2 are discussed and compared to conventional UV-activated TiO2 nanomaterials. Recent advances in bacterial disinfection using VLA TiO2 are also reviewed. Issues concerning test protocols for real visible light activity and photocatalytic efficiencies with different light sources have been highlighted.