Photocatalytic reduction - Recovery of silver using polyoxometalates

Troupis, A; Hiskia, A; Papaconstantinou, E

dc.contributor.author	Troupis, A	en
dc.contributor.author	Hiskia, A	en
dc.contributor.author	Papaconstantinou, E	en
dc.date.accessioned	2014-03-01T01:53:01Z
dc.date.available	2014-03-01T01:53:01Z
dc.date.issued	2003	en
dc.identifier.issn	09263373	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/26824
dc.subject	Photocatalysis	en
dc.subject	Polyoxometalates	en
dc.subject	Silver recovery	en
dc.subject.other	Metal recovery	en
dc.subject.other	Negative ions	en
dc.subject.other	Organometallics	en
dc.subject.other	Precipitation (chemical)	en
dc.subject.other	Reduction	en
dc.subject.other	Silver	en
dc.subject.other	Thermodynamics	en
dc.subject.other	Ultraviolet radiation	en
dc.subject.other	Redox potential	en
dc.subject.other	Photocatalysis	en
dc.title	Photocatalytic reduction - Recovery of silver using polyoxometalates	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/S0926-3373(02)00264-3	en
heal.identifier.secondary	http://dx.doi.org/10.1016/S0926-3373(02)00264-3	en
heal.publicationDate	2003	en
heal.abstract	Recovery of silver ions from aqueous solutions can be obtained through a homogeneous photocatalytic process that involves addition of a polyoxometalate (POM) (POM = PW12O403-, SiW12O404- or P2Mo18O626-) organic substrate, for instance propan-2-ol, and illumination with near-visible and UV-light. The process is effective for a wide range of Ag+ concentration, varying from about 3 to more than 1300 ppm. Prolonged irradiation leads to complete removal of silver up to non detected traces (<0.2 ppm). Silver removal follows thermodynamics, i.e. it depends on the redox potential difference of the photochemically reduced POM and Ag+ in the thermal reaction [POM(e-) + Ag+ → POM + Ag]. Air oxygen has no effect on the rate of silver recovery. On the contrary, thiosulfate complexes Ag+, lowers the redox potential and hinders the reduction and precipitation of silver. Unlike TiO2 particulates, POM anions are not contaminated by the precipitated silver retaining their ability to remove large quantities of pure metal. © 2002 Elsevier Science B.V. All rights reserved.	en
heal.journalName	Applied Catalysis B: Environmental	en
dc.identifier.doi	10.1016/S0926-3373(02)00264-3	en
dc.identifier.volume	42	en
dc.identifier.issue	3	en
dc.identifier.spage	305	en
dc.identifier.epage	315	en