Polyoxometalates hybrid material

There is little doubt that diverse physical properties common to polyoxometalates places them in an almost unmatched class of materials which could be extremely useful as hybrid materials and nanocomposites [31]. In this section we will focus on POM systems with properties that could be exploited in the development of molecular-scale devices. 

Polyoxometalates have found applications in analytical and clinical chemistry, catalysis (including photocatalysis), biochemistry (electron transport inhibition), medicine (antitumoral, antiviral, and even anti-HIV activity), and solid-state device [19,20], Recently, three-dimensional ordered materials are modified by the incorporation of POM into wall structures using a direct synthesis approach [21,22], The motivation for the work lies in the novel properties that POM is introduced into silica networks [19,20], The incorporation is that the POM is linked to silica matrix by covalent grafting. A class of POM that are particularly attractive for the preparation of hybrid materials are the lacunary POM. Lacunary POMs include the mono and divacant unsaturated Keggin fragments [X" W,039]< ">- (X"+=B Ge P [22], [ Y -SiWioOgg] [21], Lacunary... 

Ying Lu received a Ph.D degree from Northeast Normal University in 2005 under the supervision of Professor Enbo Wang. From 2006 to 2008 she worked as a Postdoctoral Fellow at the University of Ulm with Professor Dirk Volkmer. Currently she is an Associate Professor in Northeast Normal University. Her research is focused on the synthesis, structure and characterization of polyoxometalate-based organic-inorganic hybrid materials. 

Because of the considerable variety of materials that can be classified as porous, the discussion will be limited to several groups porous silicates and aluminosilicates, porous metal oxides and related compounds, porous polyoxometalates, metal-organic frameworks, porous carbons, carbon nanotubes, and several hybrid materials. All these materials can be viewed as relatively homogeneous from the electrochemical point of view. Metal and metal oxide nanoparticles, organic metals, fullerenes, and dendrimers, which can also be regarded as nanostructured materials, also displaying distinctive electrochemical features, will not be treated here for reasons of brevity, although their appearance in hybrid materials as modifiers for microporous materials will be discussed. 

Polarz, S. Smarsly, B. Goltner, C. Antonietti. M. The interplay of colloidal organization and OxO-cluster chemistry Polyoxometalate-silica hybrids—Materials with nanochemical function. Adv. Mater. 2000. 12. 1503. 

Using Dye/amine/alkyl bromide, iridium-containing photoluminescent polyacrylate films have also been manufactured. Polyoxometallate (POM)/polymer hybrid materials exhibiting modified mechanical properties (polymerized EPOX/TMPTA matrix with inserted POM clusters [XIA 15]) were synthesized in a one-step process using a silicon or phosphor polyoxomolybdate/iodonium salt/silane system. 

He, T., Yao, J. (2006). Photochromism in composite and hybrid materials based on transition-metal oxides and polyoxometalates. Progress in Materials Science, 51, 810-879. http //dx.doi.Org/10.1016/j.pmatsci.2005.12.001. 

Cannizzo, C., Mayer, C., Secheresse, R, et al. (2005). Covalent Hybrid Materials Based on Nanolatex Particles and Dawson Polyoxometalates, Adv. Mater., 17, pp. 2888-2892. 

Cuan J, Yan B (2013) Cool-white light emitting hybrid materials of resin-mesoporous silica composite matrix encapsulating europium polyoxometalates through ionic liquid linker. RSC Adv 3 20077-20084... 

Cuan J, Yan B (2014) Photofunctional hybrid materials with polyoxometalates and benzoate modified mesoporous silica through double functional imidazolium ionic liquid linkage. Microporous Mesoporous Mater 183 9-16... 

The preparation of cellulose/silica hybrid materials functionalized with Keggin-type polyoxometalates employing sol-gel synthesis tmder mild conditions has been also developed. These bio-based materials were composed by a 37 % of propylamine-modified silica dispersed over cellulosic fibres (56 wt%) and a small... 

Jin H, Wu Q, Pang W (2007) Photocatalytic degradation of textile dye X-3B using polyoxometalate-Ti02 hybrid materials. J Hazard Mater 141 123-127... 

Recently, a silica-modified magnetite particle-supported bifunctional hybrid material (IL/SMNP) combining TEMPO (2,2,6,6-tetramethylpiperidine-l-oxyl) based IL and polyoxometalate moieties was developed for aerobic oxidation of alcohol [82]. The involvement of the TEMPO moiety improves the catalytic activity dramatically. Greater than 70% yields compared to the corresponding aldehydes were obtained even using primary ahphatic alcohols such as 1-octanol as starting material. 

Polyoxometalates are important catalysts but they are also finding application in optical, electrical, and magnetic devices. Mixed-metal polyoxometalates with vanadium(V) in the polyoxoanion core confers enhanced properties to such structures, principally in their ability to form essentially infinite networks that can be utilized as coatings or as other thin film materials. Additionally, these materials have tunable electromagnetic and photochromic properties. In combination with organic polymers, so-called hybrid polymers, special electrochemical properties are conferred, making possible such electrical storage devices such as capacitors and batteries that utilize the redox properties of the polyoxometalate [7],... 

THREE-DIMENSIONAL ORDERED MACROPOROUS HYBRID SILICA MATERIALS FUNCTIONALIZED WITH LACUNARY KEGGIN-TYPE POLYOXOMETALATES PREPARATION AND CHARACTERIZATION... 

Characterization of the XMo,-Si02 materials indicated that the synthesis produced three-dimensional ordered macroporous materials with highly dispersed polyoxometalates covalently incorporated within the wall structures. IR, UV/DRS, solid-state MAS NMR spectra confirmed that the polyoxometalates remained intact in the hybrid macroporous silica materials. At first, three solid XMOu-SiOj materials all exhibited two absorptions with maxima at ca. 200 and 260 nm, respectively (Figure 1). The former is stronger and... 

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