On the other hand, silicotungstic
acid ([alpha]-H4(SiW12O40)) as an typical [alpha]-Keggin polyoxometalate could provide numbers of terminal O atoms which could construct multi-dimensional structures through coordination bonds or intermolecular hydrogen bonds with other atoms [10-16].
In this work, we have used magnetic activated carbon (MAC) nanoparticles as supporting material for an organic hybrid of silicotungstic acid (STA) to prepare a heterogeneous magnetic nanophotocatalyst.
Silicotungstic acid ([H.sub.4]Si[W.sub.12][O.sub.40]) (>99%) was purchased from Merck.
In the first step, the HMT-STA hybrid was synthesized: 10 mL hexamine aqueous solution (1.0% w/w) was added to 10 mL silicotungstic acid aqueous solution (5% w/w).
An, "Electrospinning preparation, characterization, and enhanced photocatalytic activity of an Silicotungstic acid ([H.sub.4]Si[W.sub.12][O.sub.40])/poly (vinyl alcohol)/poly (methyl methacrylate) composite nanofiber membrane," Journal of Applied Polymer Science, vol.
Guo, Phosphotungstic Acid, Silicotungstic
Acid and Silicon Tungsten-Cobalt Heteropoly Acid with Bovine Serum Albumin Interaction.
One of the inorganic materials is silicotungstic acid which is highly conductive material in the crystalline form with the structure of [H.sub.4][[W.sub.12]Si[O.sub.40]] x n[H.sub.2]O [18-22].
Silicotungstic acid hydrate [H.sub.4][Si[W.sub.12] [O.sub.40]n[H.sub.2]O, tetraethyl orthosilicate, and silica (surface area 390 [+ or -] 40 [m.sup.2]/g) were purchased from Sigma Aldrich.
Heteropoly acid matrices (IHA-D and IHA-S) made of silicotungstic acid and TEOS 65: 35 (IHA-D) and calcined silicotungstic acid and silica/TEOS 65: 35 (IHA-S) were made by silicotungstic acid and TEOS/silica [27, 28].
In case of CM-S, dehydration by calcination of inorganic heteropoly acid on support material increases the interaction anchor power with silicotungstic acid.
Polyvinyl alcohol (PVA; Alfa Aesar), KMn[O.sub.4] (Fischer Scientific), Mn[Cl.sub.2] x 4[H.sub.2]O (ACROS Organics), silicotungstic
acid ([H.sub.4][[W.sub.12]Si[O.sub.40]]) designated as STA, polyethyleneimine (PEI; Fluka), and KOH and NaOH (Aldrich) were of reagent grade and used as received.