Photocatalytic processes with tungsten oxygen anion clusters.

Photocatalytic processes with tungsten oxygen anion clusters.

Frontiers in bioscience : a journal and virtual library (2003-09-06)

Elias Papaconstantinou, Anastasia Hiskia, Aristidis Troupis

ABSTRACT

Polyoxometalates (POM) have a rich and promising photochemical behavior. Upon illumination at the O M CT band (i.e., in UV and near-visible area) become powerful oxidizing reagents able to oxidize various organic compounds. In the process POM undergo stepwise reduction accumulating electrons that can be subsequently delivered, via thermal reactions to a variety of oxidants. This way a great variety of organic compounds are oxidized and indeed mineralize to CO2, H2O and inorganic anions and several organic and inorganic compounds can be reduced via a photocatalytic process in which POM serve as electron relays. Thus, in principle, POM can serve as decontamination photocatalysts of aquatic media removing both organic pollutants and metal ions. Under special conditions controlled photocatalytic reactions have been reported. In addition the reduction precipitation of metal ions mediated by POM may lead to formation of metal nanoparticles in which POM serve as reducing reagents and stabilizers.

MATERIALS

Product Number

Brand

Product Description

267511

Sigma-Aldrich

Tungsten, powder, 12 μm, 99.9% trace metals basis

267546

Sigma-Aldrich

Tungsten, foil, thickness 0.25 mm, ≥99.9% trace metals basis

GF36484229

Tungsten, foil, 0.5m coil, thickness 0.04mm, coil width 0.7mm, as rolled, 99.95%

GF07832729

Tungsten, foil, 0.2m coil, thickness 0.6mm, coil width 1mm, as rolled, 99.95%

GF18740550

Tungsten, foil, 1m coil, thickness 0.035mm, coil width 1.5mm, as rolled, 99.95%

GF19334156

Tungsten, foil, 2m coil, thickness 0.05mm, coil width 1.5mm, as rolled, 99.95%

GF20592604

Tungsten, foil, 50x50mm, thickness 0.1mm, as rolled, 99.95%

GF53796459

Tungsten, foil, 100x100mm, thickness 0.125mm, as rolled, 99.95%

GF68135025

Tungsten, foil, 0.5m coil, thickness 0.6mm, coil width 1mm, as rolled, 99.95%

GF01998243

Tungsten, foil, 2m coil, thickness 0.035mm, coil width .75mm, as rolled, 99.95%

GF99287061

Tungsten, foil, 0.5m coil, thickness 0.05mm, coil width 1.5mm, as rolled, 99.95%

GF04494607

Tungsten, foil, 2m coil, thickness 0.076mm, coil width 1.5mm, as rolled, 99.95%

GF85971268

Tungsten, foil, 50x50mm, thickness 0.2mm, as rolled, 99.95%

GF88307309

Tungsten, foil, 0.5m coil, thickness 0.025mm, coil width .7mm, as rolled, 99.95%

GF67192544

Tungsten, foil, 0.2m coil, thickness 0.02mm, coil width .1mm, as rolled, 99.95%

GF31462163

Tungsten, foil, 150x150mm, thickness 0.5mm, as rolled, 99.95%

GF13618155

Tungsten, foil, 2m coil, thickness 0.035mm, coil width 1.5mm, as rolled, 99.95%

GF07491876

Tungsten, foil, 0.2m coil, thickness 0.04mm, coil width 0.7mm, as rolled, 99.95%

GF17364191

Tungsten, foil, 2m coil, thickness 0.08mm, coil width .9mm, as rolled, 99.95%

GF42014078

Tungsten, foil, 2m coil, thickness 0.6mm, coil width 1mm, as rolled, 99.95%

GF37965943

Tungsten, foil, 50x50mm, thickness 0.3mm, as rolled, 99.95%

GF09054053

Tungsten, foil, 1m coil, thickness 0.6mm, coil width 1mm, as rolled, 99.95%

GF74075452

Tungsten, foil, 100x100mm, thickness 0.1mm, as rolled, 99.95%

GF59431451

Tungsten, foil, 150x150mm, thickness 0.1mm, as rolled, 99.95%

GF66018999

Tungsten, foil, 2m coil, thickness 0.04mm, coil width 0.7mm, as rolled, 99.95%

GF87565135

Tungsten, foil, 10mm disks, thickness 1.0mm, as rolled, 99.95%

GF52573079

Tungsten, foil, 100x100mm, thickness 0.2mm, as rolled, 99.95%

GF99068305

Tungsten, foil, 0.5m coil, thickness 0.02mm, coil width .1mm, as rolled, 99.95%

GF28612302

Tungsten, foil, 2m coil, thickness 0.02mm, coil width .5mm, as rolled, 99.95%

GF31626716

Tungsten, foil, 0.2m coil, thickness 0.035mm, coil width .5mm, as rolled, 99.95%