LaPO4 and CePO4 nanorods/nanowires with controlled aspect ratios have been successfully synthesized using a hydrothermal microemulsion method under mild conditions. It has been shown that the obtained LaPO4 has a monoclinic structure, while CePO4 exists in the hexagonal structure. Uniform nanorods/nanowires with diameters of 20-60nm and lengths ranging from several hundreds of nanometres to several micrometres were obtained. The aspect ratios of the obtained 1D nanostructures can be fine-tuned by simply changing the [H2O]/[surfactant] molar ratios. The possible growth mechanism of LaPO4 and CePO4 nanorods/nanowires was explored in detail.

A novel photocatalyst, nanoporous anatase TiO2 crystalline particles coupled by homogeneously dispersed Keggin unit, H3PW12O40/TiO2, was prepared by a simple and rapid process, i.e., at a lower temperature (200℃) by combined sol-gel and programmed temperature hydrothermal methods. The resulting material was characterized by UV diffuse reflectant spectroscopy, XRD, 31P MAS NMR, TEM, and nitrogen adsorption. This new photocatalyst exhibited visible-light photocatalytic activity to decompose 10 various organic dyes in aqueous systems. It was attempted to determine the feasibility of such a degradation by varying the chemical structures, either azoic (Congo Red (CR), Methyl Orange (MO), Ponceau G (PG), Orange II (OII), and Eriochrome Blue Black B (EB)), or anthraquinonic (Alizarin S (AS)), or heteropolyaromatic (Methylene Blue (MB)), or fluorescent (Neutral Red (NR), Rhodamine B (RB)), or sulfonic (Fuchsin Acid (FA)). The intermediates and the final products of degradation were detected by electrospray mass spectrometer (ES-MS) and ion chromatography (IC). According to the experimental results, we proposed a possible mechanism of the photodegradation of dyes under visible-light irradiation in the aqueous system.

Heteropoly acid of Keggin structure tungstovanadogermanic (H5GeW11VO40) has been chemically anchored to the modified SBA-15 surface. The material was characterized by solid-state 29Si MAS NMR, FT-IR spectroscopy, XRD, TG-DTA and N2 adsorption experiments. The preservation of the structure of the HPA and dispersion of the cluster on the support were verified. On the bases of the spectroscopic evidences, HPA clusters were attached firmly to the surface.

A new solid high-proton conductor decatungstomolybdovanadogermanic heteropoly acid (HPA) H5GeW10- MoVO40 21H2O has been synthesized for the first time by stepwise acidification and stepwise addition of solutions of the component elements. The product was characterized by chemical analysis, potentiometric titration, IR, UV, XRD and TG-DTA. The IR, UVand XRD indicate that H5GeW10MoVO40 21H2O possesses the Keggin structure. The TG-DTA curve shows the sequence of water loss in the acid, the amount of the loss, as well as the thermostability. The results of AC impedance measurement show that its proton conductivity is 3.58×10-4 S cm-1 at 18℃ and the activation energy for proton conduction is 31.82kJ/mol.

The decatungstodivanadogermanic heteropolyacid H6GeW10V2O40.22H2O was synthesized for the first time by the stepwise acidification and the stepwise addition of solutions of the component elements. The product was characterized by means of inductively coupled plasma (ICP), IR, UV, X-ray diffraction and thermal analysis. The results of AC impedance measurement show that its proton conductivity is 1.20×10-2 S.cm-1 at room temperature (16℃).

Polypyrrole (PPy) hybrid material doped vanadotungstogermanic triheteropoly acid was prepared for the first time. Their SEM, IR and XRD patterns confirm the existence of Keggin anions and form the space reticular structure. The material exhibits excellent proton conduction, its proton conductivity is 1.24×10−2 S cm−1 at room temperature (18℃).

Silica gels composited with undecatungstochromoferrous acid have been prepared by the sol-gel method. FT-IR spectra and SEM declared that theKeggin structure characteristic of the Fe(H2O)CrW11O39 6−anionwas found in the silica gel skeleton. The change of characteristic peaks in IR spectra was analyzed. XRD pattern showed that the gel was amorphous. The gel exhibited considerably high-proton conductivity, which increased from 1.88×10−3 to 1.11×10−2 S cm−1 with the increase of the content of undecatungstochromoferrous acid at 20℃.

The decatungstomolybdoniobogermanic heteropoly acid H5 [GeW10MoNbO40] 20H2O has been prepared for the first time. The optimal proportion of the solutions of the component and the pH of the synthesis reaction are given. The product was characterized by chemical analysis, conductometric and potentiometric titration, IR, UV, XRD, 183W NMR and TG-DTA. The IR, UV, XRD and 183WNMR indicate that H5 [GeW10MoNbO40] 20H2O possesses the Keggin structure. The TG-DTA curve shows the sequence of water loss in the acid, the amount of the loss as well as the thermostability of the acid.

PVA films containing 12-tungstogermanic heteropoly acid have been successfully prepared for the first time. Infrared (IR) spectra revealed that the Keggin structure characteristic of the GeW12O440y anion was present in the PVA films. The characteristic IR peaks have been identified and their change in wave number interpreted as a function of heteropoly acid (HPA) content. The film exhibited considerably high proton conductivity, which increased with the increase of the 12-tungstogermanic heteropoly acid content. At room temperature (208C）, the conductivity of the PVA film containing 80 wt.% 12-tungstogermanic heteropoly acid is 2.11=10y2 S cmy1. The photochromism of the PVA film was observed. Its color changed into blue. q2001 Elsevier Science B.V. All rights reserved.

The vanadotungstogermanic heteropoly acid H3 GeW11 VO40 22H2O has been prepared for the first time by the stepwise acidification and the stepwise addition of solutions of the component elements. The suitable condition for the synthesis reaction is given. The product was characterized by means of ICP, potentiometric titration, IR, UV, V NMR, X-ray powder 23 diffraction and thermal analysis. The result of AC impedance measurement shows that its proton conductivity is 2.43×10-3 S cm-1 at 18℃.