Visible-light response

Tsuji I, Kato H, Kobayashi H, Kudo A (2004) Photocatalytic H2 evolution reaction from aqueous solutions over band structure-controlled (AgIn)xZn2(i-x)S2 solid solution photocatalysts with visible-light response and their surface nanostructures. J Am Chem Soc 126 13406-13413... 

Pure Ti02 was recently reported to be active in the disinfection of water contaminated by spores of the type Fusarium solani [142], Bacillus anthracis [143], or Cryptosporidium parvum oocysts [144], or when supported as nanocomposites on zeolite H(i for E. coli deactivation [145], and it found applications in water treatment as a replacement for chlorine. Ag-Ti02 immobilized systems were used for inactivation of bacteria, coupling the visible light response of the system and the strong bactericidal effect of Ag [146]. Silver was deposited on hydroxyapatite to form nanocomposites with a high capacity for bacterial adsorption and inactivation [147], or used for airborne bacterial remediation in indoor air [148],... 

Wu, J.C.S and Chen, C.H. (2004) A visible-light response vanadium-doped titania nanocatalyst by sol-gel method. 

Kuo, C.S., Tseng, Y.H., Huang, C.H., and Li, Y.Y. (2007) Carbon-containing nano-titania prepared by chemical vapor deposition and its visible-light-responsive photocatalytic activity. Journal of Molecular Catalysis A Chemical, 270 (1-2), 93-100. 

Okada, M., Yamada, Y., Jin, P., Tazawa, M., and Yoshimura, K., Fabrication of multifunctional coating which combines low-e property and visible-light-responsive photocatalytic activity, Thin Solid Films, 442,217,2003. 

Mohamed, A. E. R. Rohani, S., Modified Ti02 nanotube arrays (TNTAs) progressive strategies towards visible light responsive photoanode, a review. Energy Environ. Sci. 2011,4 1065-1086. 

Fujishima A, Honda K (1972) Electrochemical photolysis of water at a semiconductor electrode. Nature 238 37-38 Yamashita H, Harada M, Misaka J, Takeuchi M, Neppolian B, Anpo M (2003) Photocatalytic degradation of organic compounds diluted in water using visible light-responsive metal ion-implanted Ti02 catalysts Fe ion-implanted Ti02. Catal Today 84 191-196... 

Fig. 6.10 Z-scheme system for water splitting by a two-photon process with visible light response [149],...

Ultraviolet Radiation The portion of the electromagnetic spectrum emitted by the sun adjacent to die violet end of die visible light range. Often called black light , it is invisible to the human eye but when it falls on certain surfaces it causes them to fluoresce or emit visible light responsible for the photo-oxidation of certain compounds including hydrocarbons. 

Takeuchi K, Nakamura I, Matsumoto O, Sugihara S, Ando M, Ihara T. Preparation of visible-light-responsive titanium oxide photocatalysts by plasma treatment. Chem Lett 2000 1354-1355. 

Nahar, S., K. Hasegawa and S. Kagaya (2006). Photocatalytic degradation of phenol by visible light-responsive iron-doped Ti02 and spontaneous sedimentation of the Ti02 particles. Chemo-sphere, 65(11), 1976-1982. 

Nakamura, R., T. Tanaka and Y. Nakato (2004b). Mechanism for visible light responses in anodic photocurrents at n-doped Ti02 film electrodes. Journal of Physical Chemistry B, 108(30), 10617-10620. 

Kitano, M., Takeuchi, M., Matsuoka, M., Thomas, J. M. and Anpo, M. (2005). Preparation of visible light-responsive Ti02 thin film photocatalysts by an RF magnetron sputtering deposition method and their photocatalytic reactivity. Chem. Lett. 34(4), 616-617. 

Visible-Light-Response and Photo-catalytic Activities of TiCL and SrTiCh Photocatalysts Co-doped with Antimony and Chromium. The band gap of SrTiCh shrunk to 2.4 eV by co-doping. 409... 

Nickel and Either Tantalum or Niobium-Co-doped TiCh and SrTiCh Photocatalysts with Visible-Light Response for H2 or O2 Evolution from Aqueous Solutions Co-doping found to afford higher activity for HER compared with Ni alone. 334... 

Cation or anion doping Ion doping has been extensively investigated for enhancing the visible-light response of wide band-gap photocatalysts (UV-active). Examples include Sb- or Ta- and Cr-doped Ti02 and SrTiOs (Kato et al., 2002 Ishii et al., 2004), ZnS doped with Cu or Ni (Kudo and Sekizawa, 1999 Kudo and Sekizawa 2000), or C-doped Ti02 (Khan et al., 2002). 

Figure 11 Band structure of cation-doped photocatalyst with visible light response from a semiconductor with wide band gap (UV response) (Kudo, 2003).

Composite semiconductors Semiconductor mixing (composite) is another strategy for developing photocatalysts with visible-light response from photocatalysts with a wide band gap. This strategy is based on the coupling of a wide band-gap semiconductor with a narrow band semiconductor with... 

Figure 13 Band structure of the photocatalyst composite with enhanced visible-light response made from the mixture between wide and narrow band-gap photocatalysts.

Semiconductor alloys The third approach to the extension of the visible-light response of wide band-gap photocatalysts involves making solid solutions between wide and narrow band-gap semiconductors with a similar lattice structure as depicted in Figure 14. 

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