The Extent of the Photochemical Reduction of Phosphotungstic Acid

Abstract

Phosphotungstic acid, H3PW12O#, has been reduced by t'-propyl alcohol under the influence of sunlight to a black product which precipitated silver from silver nitrate solution, while undergoing oxidation to the starting material. One molecule of HaPWiiOw after reduction precipitated one atom of silver from solution. Thus the reduced acid was in a state of oxidation equivalent to HjPWiaO»).

Polyoxometalate‐assisted Metal Nanomaterials Synthesis#

“…Above all, the photochemical reduction strategy, which was first reported by Chakley in 1952, has been generally used for the synthesis of NPs. 17 As shown in Figure 2, POMs are reduced in the presence of sacrificial organic electron donors, which are oxidizable substrates, such as alcohol or organic pollutants, under UV irradiation and then the reduced POMs also reduce metal ions to their zero-state form. Silver Nanomaterials.…”

“…[12][13][14][15][16] In recent years, POMs have been introduced for use in the synthesis of nanomaterials as reducing and stabilizing agents, and these synthetic methods have been proposed in many publications. POMs can be reduced photochemically, 17 electrochemically, 18 or radiochemically, 19 or using suitable chemical reducing reagents 20 without decomposition or change in their structural configuration; the reduced POMs then have the capability to reduce metal ions. 21,22 The synthesized nanomaterials present negative charges due to the presence of POMs on their surface, which can prevent aggregation of the nanomaterials by electrostatic repulsion, enabling longterm stability.…”

Arsenomolybdates for Photocatalytic Degradation of Organic Dyes

“…POMs is one of the most outstanding materials in modern chemistry, as the metal-oxide clusters with abundant structures and interesting properties [1][2][3][4][5][6], which render them to potential applications in electrochemistry [7,8], photochemistry [9,10], catalytic fields [11,12], and so on (Figure 1). Chalkley reported the photoredox conversion of H 3 [PW 12 O 40 ] into a reduced POM by photoirradiation with UV light in the presence of 2-propanol as a reducing reagent in 1952 [13]. Hill et al started systematic investigation of photoredox catalysis using POMs in the 1980s [14].…”

Photocatalytic processes with tungsten oxygen anion clusters

“…The first notice on the photochemical properties of POM was published in 1916 (2) followed by another one sometime later 1952 (3). It was also observed in the early sixties that POM precipitated out with dioxane and exposed to light turned blue, the characteristic color of the reduced POM (4).…”