Visible Light-Responsive Titanium Oxide Photocatalysts: Preparations Based on Chemical Methods

Abstract

A review is presented on the present status of titania-based visible light-active photocatalysts prepared by chemical methods, with particular focus on developments made by the authors' group in doping TiO 2 with either transition metals (tungsten, iron or vanadium) or light electronegative elements such as nitrogen, and highlighting the importance of dopant concentration and of separating the effects of improved absorption spectrum range from those of recombination or surface modification.

Microwave-assisted sol-gel synthesis of an Au-TiO2 photoanode for the advanced oxidation of paracetamol as model pharmaceutical pollutant

“…The sol-gel technique offers advantages to support metal catalysts, since the active metal and support can be prepared in a single step [31,32]. Recently, novel microwave-and ultrasound-assisted processing methods are also being reported [16,21,33,34].…”

V-substituted In2S3: an intermediate band material with photocatalytic activity in the whole visible light range

“…In the context of the present work it is worth mentioning that, while TiO 2 is the material most usually considered for photocatalysis and a number of other materials have been assayed for photocatalysis, 24 In 2 S 3 has been considered previously as a photocatalyst by a signicant but smaller number of other authors. 25 As a procedure to improve the spectral response of a photocatalyst, doping of the latter (among other methods 26 ) is frequently considered, particularly in the case of TiO 2 , but normally the aim is just a decrease in the bandgap, not allowing a two-photon process, in order to make the material visible light-responsive, 27 and in any case this has not been tried for In 2 S 3 by other groups; the above mentioned work by Ho 16 is only concerned with photovoltaic behaviour. Note, nally, that an improvement in photocatalytic efficiency can be obtained also via coupling to another material which may help separating electrons and holes; this has been done occasionally with In 2 S 3 itself.…”