Visible-light illumination

C. Li, Sulfur-substituted and zinc-doped In(OH)3 A new class of catalyst for photocatalytic H2 production from water under visible light illumination, J. Catal. 237 (2006) 322-329. 

Solarska R, Santato C, Jorand-Sartoretti C, M. Ulmann and J. Augustynski (2005) Photoelectrolytic oxidation of organic species at mesoporous tungsten trioxide film electrodes under visible light illumination. J Appl Electrochem 35 715-721... 

Mrowetz M, Balcerski W, Colussi AJ, Hoffmann MR (2004). Oxidative power of N-doped Ti02 photocatalysts under visible light illumination J Phys Chem B 108 17269-17273... 

Ohno T, Akiyoshi M, Umebayashi T, Asai K, Mitsui T, Matsumura M (2002) Preparation of S-doped Ti02 photocatalysts and their photocatalytic activites under visible light. Appl Catal A Gen 265 115-121 Miyauchi M, Takashio M, Tobimatsu H (2004) Photocatalytic activity of SrTiOs codoped with nitrogen and lanthanum under visible light illumination. Langmuir 20 232-236... 

Table I shows the effect of visible light illumination before raising the temperature of the irradiated glasses. It appears that polymerization is not initiated at the polymerization temperature in the absence of anion radicals in the glasses. The small but not zero values of conversion for the illuminated glasses may result from incomplete bleaching of the anion radicals, the diameter of the polymerization vessels (20 mm) being much larger than that of the ESR sample tubes (4 mm). The effect of pre-illumination on the conversion indicates that the anion radicals are involved in the initiation process of the radiation-induced polymerization of nitroethylene.

Fukushima et al. reported analogously modified / -CD [50] and y-CD [51] with shorter spacer. Association of regioisomer E takes place in concentrated solutions. Upon UV irradiation the / -CD dimer dissociate and returns to its original form by visible light illumination. Isomer Z of this compound does not form dimers. In aqueous solution, the y-CD derivative upon UV induced photoisomerization afforded 79% cis form at the photostationary state. The half-life of this isomer is 34 h in dark. 

Wu T, Liu G, Zhao J, Hidaka H, Serpone N. Evidence for H202 generation during the Ti02-assisted photodegradation of dyes in aqueous dispersions under visible light illumination. J Phys Chem B 1999 103 4862-7. 

Based on their experimental results concerning ethanol and methanol photooxidation by Au/Ti02 composites under visible-light illumination, Tatsuma et al. (Tian and Tatsuma 2005) proposed a plasmon-induced charge separation scheme. They observed a surprising phenomenon, in which the photoelectrons were excited from Au nanoparticles and transferred to the CB of Ti02 (Wood et al. 2001 Subramanian et al. 2004). Meanwhile, the oxidized Au species accepted electrons from the donor molecules present in the solution to recover the charge balance. The process is illustrated in Fig. 16.23. 

Zhao et al. (2002) studied the photodestruction of sulforhodamine-B in Pt/Ti02 suspension under visible light illumination. The electrons excited from dye molecules were accepted by Pt islands. The accumulated electrons then react with 02 to form 02- and subsequently OH, which ultimately caused the self-destruction of the dye molecules. Photocatalytic destruction of oxalic acid (Iliev et al. 2006) and H2 generation (Sreethawong et al. 2006) from aqueous methanol solution were also promoted by platinizing Ti02. Under anoxic conditions, products from... 

X Li, D. Wang, G. Cheng, Q. Luo, J. An, Y. Wang, Preparation of polyaniline-modified Ti02 nanoparticles and their photocatalytic activity under visible light illumination . Applied Catalysis B Environmental, 81, 24, 267-273, (2008). 

The latest systems appear to work under visible light illumination without a noble metal-based H2 and/or O2 catalyst There have been reported photocatalysts such as delafossite CuFe02, without a separate H2 or O2 catalyst, or In/NiAra-oxides coated with NiO, or RUO2 for visible-light activated water-splitting processes. However, all reported water-splitting systems are controversial and require confirmation [3]. 

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