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

267546

Sigma-Aldrich

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

GF69782349

Tungsten, insulated wire, 5m, conductor diameter 0.075mm, insulation thickness 0.02mm, PTFE (polytetrafluoroethylene) insulation, 99.9%

GF91891266

Tungsten, insulated wire, 10m, conductor diameter 0.05mm, insulation thickness 0.008mm, polyimide insulation, 99.9%

GF18063783

Tungsten, microfoil, disks, 10mm, thinness 0.25μm, specific density 474μg/cm², permanent mylar 3.5μm support, 99.95%

GF14483088

Tungsten, insulated wire, 0.2m, conductor diameter 0.015mm, insulation thickness 0.002mm, polyimide insulation, 99.9%

GF31324384

Tungsten, foil, 5m coil, thickness 0.025mm, coil width 1mm, as rolled, 99.95%

GF35250005

Tungsten, foil, not light tested, 50x50mm, thickness 0.004mm, 99.95%

GF28186072

Tungsten, foil, light tested, 150x150mm, thickness 0.05mm, as rolled, 99.95%

GF21631250

Tungsten, lump, 200g, max. size 5mm

GF38958250

Tungsten, insulated wire, 2m, conductor diameter 0.075mm, insulation thickness 0.02mm, PTFE (polytetrafluoroethylene) insulation, 99.9%

GF84684808

Tungsten, rod, 200mm, diameter 6.35mm, centerless ground, 99.95%

GF41314092

Tungsten, foil, light tested, 50x50mm, thickness 0.075mm, as rolled, 99.95%

GF06146805

Tungsten, foil, not light tested, 25x25mm, thickness 0.004mm, 99.95%

GF79060103

Tungsten, insulated wire, 2m, conductor diameter 0.025mm, insulation thickness 0.005mm, polyimide insulation, 99.9%

GF52817878

Tungsten, foil, 30mm disks, thickness 1.0mm, as rolled, 99.95%

GF32754595

Tungsten, foil, light tested, 150x150mm, thickness 0.075mm, as rolled, 99.95%

GF79938039

Tungsten, lump, 50g, max. size 5mm

GF52385799

Tungsten, insulated wire, 1m, conductor diameter 0.015mm, insulation thickness 0.002mm, polyimide insulation, 99.9%

GF90717666

Tungsten, microfoil, disks, 10mm, thinness 0.05μm, specific density 96μg/cm², permanent mylar 3.5μm support, 99.95%

GF75672254

Tungsten, insulated wire, 2m, conductor diameter 0.0125mm, insulation thickness 0.0035mm, polyimide insulation, 99.9%

GF11784449

Tungsten, foil, light tested, 150x150mm, thickness 0.025mm, as rolled, 99.95%

GF73441199

Tungsten, microfoil, disks, 10mm, thinness 0.1μm, specific density 182μg/cm², permanent mylar 3.5μm support, 99.95%

GF95973216

Tungsten, wire reel, 0.5m, diameter 1.0mm, clean, 99.95%

GF24694049

Tungsten, insulated wire, 2m, conductor diameter 0.015mm, insulation thickness 0.002mm, polyimide insulation, 99.9%

GF10563342

Tungsten, foil, not light tested, 50x50mm, thickness 0.007mm, 99.95%

GF86719461

Tungsten, foil, not light tested, 25x25mm, thickness 0.006mm, 99.95%

GF27394702

Tungsten, mesh, 100x100mm, nominal aperture 0.2mm, wire diameter 0.05mm, 100 wires/inch, open area 64%, plain weave mesh, 99.95%

GF43142969

Tungsten, foil, light tested, 25x25mm, thickness 0.025mm, as rolled, 99.95%

GF31886589

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

GF59032481

Tungsten, insulated wire, 5m, conductor diameter 0.0125mm, insulation thickness 0.0035mm, polyimide insulation, 99.9%