Assembly of Polyoxometalate-Based Composite Materials

Abstract

This paper is a review the polyoxometalatebased composite materials, including polyoxometalate incorporated Langmuir and Langmuir-Blodgett, layerby-layer multilayers and novel honeycomb films, selfassembly structures of modified polyoxometalate complexes (e.g., onion-like structures, new inorganic-organic-inorganic vesicles, thermotropic and lyotropic liquid crystalline structures, gels), and amino acid-and protein-polyoxometalate nanorods and nanoparticles. Polyoxometalate-embedded layer-by-layer multilayer films show electrocatalytic or photochemical activity; and, novel photoluminescent honeycomb films templated by microwater droplets are reviewed. Inorganic-organic-inorganic hybrid vesicles display the potential as nano-switches. In addition, amino acid-and proteinpolyoxometalate composite nanostructures indicate potential antimicrobial applications. Therefore, the polyoxometalatebased composite materials have promising applications in electrochemistry, photochemistry and biomedicine.

Antibacterial activity of some saturated polyoxotungstates

“…SiW 12 had similar inhibitory activity with PW 12 on MDR Pseudomonas and Staphylococcus spp. ; in contrast, on the rest of the strains, the MICs were almost double for PW 12 . Na 3 PW 12 had a very poor action, especially on Enterococcus and Klebsiella, where MIC equaled MBC.…”

“…Both PW 12 and SiW 12 inhibited the growth of bacteria at about the same concentration values (for PW 12 = 206.18-972.6 mg/ml, and for SiW 12 = 205.93-971.4 mg/ml). On E. coli, SiW 12 had action only at high concentrations (from 845 to 971.4 mg/ ml), whereas PW 12 did not show any effect.…”

“…All the compounds used for this study are saturated Keggin structures, with general formula [XM 12 O 40 ] n-involving a XO 4 tetrahedron surrounded by twelve MO 6 octahedral that are arranged in four groups of three octahedral linked by common sides. These groups of triplet are linked by common peaks with central tetrahedron (9).…”

“…Unique structural and electronic properties of this class of compounds makes them to find their applications in many fields of science and technology, among which: chemical analysis, catalysis, biochemical applications, reagents for chemical analysis, ion exchange, thin-layer chromatography, etc (10)(11)(12)(13). POMs' catalytic properties were described by Papaconstantinou and Mylonas in water decontamination of aliphatic and aromatic representative compounds (14) (16)(17)(18).…”

Electrochemical behavior of Keggin-type heteropolyanion doped composite of polyaniline and multi-walled carbon nanotubes

“…Assembly of polyoxometalates embedded in ordered structures has become a research hotspot in order to obtain more functional composite materials [11]. Molybdophosphoric acid H 3 PMo 12 O 40 ·nH 2 O (PMo 12 ) is a classic Keggin-type heteropoly acid molecule.…”