Introduction by the guest editors

This issue of Photochemical & Photobiological Sciences contains a collection of papers presented at the 5th European Meeting on Solar Chemistry and Photocatalysis: Environmental Applications (SPEA 5). The conference, held in Palermo (Italy) from 4th to 8th October 2008, was organized by Leonardo Palmisano and Vincenzo Augugliaro. The 252 delegates (representing 757 authors) came from many different European and non-European countries.

The biennial SPEA conference places strong emphasis on research in photochemical and photocatalytic processes able to use natural or simulated sunlight, not only for abating pollutants present in liquid and gas effluents, but also their potential for green chemistry (mild experimental conditions, non-hazardous solvents and reagents, etc.) for organic syntheses that afford important chemicals.

Among the published papers we would like to mention those by Arslan-Alaton et al, Fornasiero et al., Olmez-Hanci et al., Peralta-Hernández et al., Silva and Faria, and Vilar et al. on the photodegradation of pollutants in liquid systems. Some of these compare the efficiency of different photochemical technologies (e.g. photo-Fenton, H₂O₂/UV, heterogeneous photocatalysis).

Krichevskaya et al. deal with the photocatalytic oxidation of acrylonitrile in the presence of TiO₂ in a gas–solid system, using an annular continuous-flow reactor. An annular photocatalytic slurry reactor for water treatment is presented by Camera-Roda et al.

Water disinfection of drinking water by solar energy was addressed by McGuigan et al. (inactivation efficiency of the UVA dose), and water disinfection using artificial light was reported by Labas et al. The papers by Yamashita et al., Lianos et al., Bahnemann et al., Ctibor et al., Černigoj et al., Cerc Korošec et al., and Augugliaro et al. report on preparation of efficient photocatalysts (also as films) for hydrogen production or for photooxidation.

Augugliaro et al. report that for selective photocatalytic synthesis, e.g. photooxidation of 4-methoxybenzyl alcohol to 4-methoxybenzaldehyde, samples of TiO₂ prepared in-house are weaker oxidants and more selective than some commercial samples. In the same sense, Ciambelli et al deal with selective photooxidation of ethanol, and the paper by Maldotti et al. also focuses on partial photooxidation of allylic and primary alcohols. Klementováet al. summarize some fluorescence results and report on interaction between humic substances and metals.

The paper by Falaras et al. addresses synthesis and characterization of ruthenium(II) complexes to be used in dye-sensitized cells (DSC). Litter et al. demonstrate that the reduction of Cr(VI) species to the less hazardous Cr(III) can be achieved by adsorption of hydroxoaluminium tricarboxymonoamidephthalocyanine onto the TiO₂ surface, which injects electrons into the conduction band of the semiconductor by visible light excitation. 4-Chlorophenol was used as the model donor.

The contribution of Agüera et al. evaluates the photodegradation pathway and toxicity of an aqueous system containing quinolone antibiotics resistant to conventional wastewater treatments after photocatalytic treatment.

The invited editors wish to express their appreciation to all the authors for their contributions and are confident that this collection of papers, although not exhaustive, reflects the most relevant aspects of the state of the art and the excellent perspectives for application of the processes described.

 

Vincenzo Augugliaro

 Università di Palermo, Palermo, Italy. E-mail: augugliaro@dicpm.unipa.it

Leonardo Palmisano

 Università di Palermo, Palermo, Italy. E-mail: palmisano@dicpm.unipa.it

Sixto Malato

 Plataforma Solar de Almería, Almería, Spain. E-mail: Sixto.Malato@psa.es

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