The Research Progresses Of Silver Salt Photocatalysts And The Determination For Solubility Product Of Phosphomolybdatesilver

The silver salts (including the silver halide, silver phosphate, silver vanadium oxide and silver doped various semiconductor) are excellent photocatalytic materials. Since the silver salt photocatalysis can form surface plasmon resonance effect, they have highly efficient photocatalytic activities. Recently, people pay more attention to them. In this paper, the Research Progresses of Silver Salt Photocatalysts recent years are reviewed.The silver salt of polyoxometalates (POMs), combining with the advantages of Ag and POMs, have potential applications in catalysis especially in the field of photocatalysis. The synthesis of such compound, the determination of the solubility product, the physical and chemical properties of it and other aspects of the basic research have an important significance for the further development of the POMs-based silver salt photocatalytic materials. A new insoluble silver salt of Keggin-type polyoxometalate, Ag3PMo12O40·4H2O(1) was synthesized by ion-changed reaction of Keggin-type [PM012O40]3" and silver nitrate. Compound1was characterized by elemental analysis (ICP), infrared spectrum (IR), and thermogravimetric analysis (TGA). Compound1is insoluble in water. There is precipitation equilibrium in aqueous solution. Therefore, we determined the Ksp of1by the methods of spectrophotometry and ion resin exchange at25℃, then calculated the standard electrode potential of Ag3PMo1204o/Ag based on the results of Ksp by Nernst equation. The Ksp of1determined by the two methods were2.25×10-10and2.08×1010, respectively. On that basis, the standard electrode potential of Ag3PMo1204o/Ag were also worked out by Nernst equation, results were0.6092V and0.6085V. The two methods are close, and the experimental results show that they were in reasonable agreement. Compound1is yellow and sensitive to natural light which means that it has potential applications in the visible light photocatalysis. In this paper, the synthesis and characterization of the compound1and its solubility product and the standard electrode potential application in the field of photocatalysis provide the theoretical basis for the further exploration.