Mesoporous silica pillared clay (SPC) incorporated with tungstophosphoric acid (HPW) has been synthesized via in situ introducing P and W source in the acidic suspension of the clay interlayer template during the formation of the silica pillared clay. The samples were characterized by XRD, XRF, FT-IR, TG-DTA, N(2) adsorption-desorption, and SEM techniques. The results showed that the HPW formed...

A simple method to embed noble metal (Ag, Au) nanoparticles in organic–inorganic nanocomposite films by single step method is described. This is accomplished by the assistance of Keggin ions present in the composite film. The photochemically reduced composite film has served both as a reducing agent and host for the metal nanoparticles in a single process. The embedded metal nanoparticles in co...

Despite the ubiquity of ferrihydrite in natural sediments and its importance as an industrial sorbent, the nanocrystallinity of this iron oxyhydroxide has hampered accurate structure determination by traditional methods that rely on long-range order. We uncovered the atomic arrangement by real-space modeling of the pair distribution function (PDF) derived from direct Fourier transformation of t...

The asymmetric unit of the title compound, [Zn(C(8)H(7)N(3))(3)](2)[SiMo(12)O(40)]·6H(2)O, consists of a complex [Zn(C(8)H(7)N(3))(3)](2+) cation, half of a Keggin-type [SiMo(12)O(40)](4-) heteropolyanion and three uncoordinated water mol-ecules. The Zn(2+) cation is surrounded in a distorted octa-hedral coordination by six N atoms from three chelating 3-(2-pyrid-yl)pyrazole ligands. In the het...

The five manganese-containing, Keggin-based tungstosilicates [Mn(II)3(OH)3(H2O)3(A-α-SiW9O34)](7-) (1), [Mn(III)3(OH)3(H2O)3(A-α-SiW9O34)](4-) (2), [Mn(III)3(OH)3(H2O)3(A-β-SiW9O34)](4-) (3), [Mn(III)3Mn(IV)O3(CH3COO)3(A-α-SiW9O34)](6-) (4), and [Mn(III)3Mn(IV)O3(CH3COO)3(A-β-SiW9O34)](6-) (5) were synthesized in aqueous medium by interaction of [A-α-SiW9O34](10-) or [A-β-SiW9O34H](9-) with eit...

Zunyite [Al13Si5O20(OH,F)18Cl] possesses an unusual combination of an Al13O16(OH)24 Keggin structure and a Si5O16 pentamer unit. We used 19F, 27Al, 29Si MAS and 27Al MQMAS NMR spectroscopy of a series of samples with varying Al:Si and F:OH ratios to investigate the degree of atomic order in zunyite. The quadrupole coupling constant (CQ) and asymmetry parameter ( ) obtained from simulations of 2...

The solution chemistry of a series of mono-, di- and trilacunary Keggin silicotungstates was investigated by electrospray ionization mass spectrometry (ESI-MS) and general electrospray features especially for lacunary POMs are summarized. The reactions of vanadium incorporation into the lacunary structures were successfully monitored in real-time by a combination of ESI-MS and differential puls...