title: Surfactant-assisted synthesis of Keggin-type polyoxometalates nanorods.
abstract: It was demonstrated that Keggin-type polyoxometalates nanorods (POMs-nanorods) were prepared from a solution containing a surfactant polyethylene glycol (PEG), when heteropolyanions [X(n+)M12O40](-(8-n)) (X(n+) = P5+ and Si4+; M = W and Mo) were precipitated by ammonia ion obtained by hydrolysis of urea at 373 K. In this method, PEG was used as a template and ammonia ion (NH4+) was a counterion. In an oil bath kept at 373 K without stirring, three kinds of ammonium salts of POMs, i.e., (NH4)3PW12O40, (NH4)4SiW12O40, and (NH4)3PMo12O40 nanorods were obtained. The POMs-nanorods were characterized by transmission electron microscopy (TEM), selected area electron diffraction (SAED), infrared spectra (IR), inductively coupled plasma atomic emission spectrometry (ICP-AES) and X-ray powder diffraction (XRD). TEM showed that nanorods were 0.5-1.5 microm in length, and 50-150 nm in diameter. The results of IR, ICP-AES and XRD proved the existence of Keggin structure. The formation process of POMs-nanorods, (NH4)(8-n) [X(n+)M12O40](-(8-n)) (X(n+) = P5+ and Si4+; M = W and Mo) in a H2O/PEG system was discussed.
authors.affiliation: Institute of Polyoxometalate Chemistry, Faculty of Chemistry, Northeast Normal University, Changchun, 130024, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yang
authors.forename: Minhua
authors.initials: M
authors.lastname: Cao
authors.forename: Changwen
authors.initials: C
authors.lastname: Hu
authors.forename: Yihang
authors.initials: Y
authors.lastname: Guo
authors.forename: Enbo
authors.initials: E
authors.lastname: Wang
mesh_terms: D004583:Electrons; D006868:Hydrolysis; D007477:Ions; D046529:Microscopy, Electron, Transmission; D008956:Models, Chemical; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology; D043942:Nanotubes / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D013055:Spectrophotometry, Infrared; D013501:Surface-Active Agents / Q000737:chemistry*; D013696:Temperature; D017973:Tungsten Compounds / Q000737:chemistry*; D014508:Urea / Q000737:chemistry; D014961:X-Ray Diffraction; D000099294:Polyoxometalates
chemical_list: D007477:Ions; D011092:Polyethylene Glycols; D013501:Surface-Active Agents; D017973:Tungsten Compounds; D014508:Urea; C102296:polyoxometalate I; D000099294:Polyoxometalates