Novel nano-structured clays were synthesized from cation exchange reaction by the intercalation of rhodium complexes with ligand spacers into clay. Expansion of interlayer space of the modified clays depends on the spacers. A unique conformation of pillar complexes was detected by cross polarization magic angle spinning (CP MAS) NMR.

The vaporization behavior of silicon and three refractory trace elements (Al, Ti and Y) were studied in the presence and absence of a PTFE emulsion as fluorinating reagent and applying an electrothermal ICP-AES coupled system.It was found that during a 60 s ashing step at 700℃ about 90% of 100mg of Si3N4 can be decomposed and evaporated without considerable losses of the trace elements investigated. Calibration could be carried out by the standard addition method and the calibration curve method applying spiked slurries and aqueous standard solutions with peak height intensity measurements, respectively. The detection limits varied from 0.11 mg g−1 (Al) to 0.09mg g−1 (Ti) with RSD 1.9-4.2%.

A new analytical procedure for the direct determination of metal impurities (Cr, Cu, Fe and V) in aluminium oxide ceramic powders by slurry sampling fluorination assisted electrothermal vaporization-inductively coupled plasma-atomic emission spectrometry (ETV-ICPAES) is reported. A polytetrafluoroethylene (PTFE) emulsion was used as a fluorinating reagent to promote the vaporization of impurity elements in aluminium oxide ceramic powders from the graphite tube. A vaporization stage with a long ramp time and a short hold time provided the possibility of temporal analyte-matrix separation. The experimental results indicated that a 10μL1% m/v slurry of aluminium oxide could be destroyed and vaporized completely with 600μg PTFE under the selected conditions. Two aluminium oxide ceramic powder samples were used without any additional pretreatment. Analytical results obtained by using standard addition method with aqueous standard solution were checked by comparison of the results with pneumatic nebulization (PN)-ICP-AES based on the wet-chemical decomposition and analyte-matrix separation. The limits of detection (LODs) between 0.30μg g-1 (Fe ) and 0.08μgg-1 (Cu) were achieved, and, the repeatability of measurements was mainly better than 10%.

Cerium-doped mesoporous TiO2 nanoparticles with high surface area and thermal stable anatase wall were synthesized via hydrothermal process in a cetyltrimethylammonium bromide (CTAB)/Ti(SO4)2/Ce(NO3)4/H2O system. The obtained materials were characterized by XRD, FESEM, HRTEM, FTIR spectroscopy, nitrogen adsorption and DRS spectra. Experimental results indicated that the doping of cerium not only increased the surface area of mesoporous TiO2 nanoparticles, but also inhibited the mesopores collapse and the anatase-to-rutile phase transformation. Moreover, the undoped, doped anatase mesoporous nanoparticles exhibit higher photocatalytic activity than commercial photocatalyst (Degussa, P25), but the maximum photodegradation rate corresponds to the undoped mesoporous TiO2 nanoparticles. The lower photocatalytic activities of cerium-doped samples compared with undoped one may be ascribed to that the doped cerium partially blocks titania's surface sites available for the photodegradation and absorption of Rhodamine B (RB).

Lanthana-doped mesoporous TiO2 nanoparticles with high specific surface area and thermal stable anatase wall was synthesized via hydrothermal process by using cetyltrimethylammonium bromide (CTAB) as surfactant-directing agent and pore-forming agent. The resulting materials were characterized by XRD, FESEM, TEM, FT-IR spectroscopy, and nitrogen adsorption. The as-synthesized mesoporous doped TiO2 nanoparticles have mean diameter of 20nm with mean pore size of 2.2nm. The specific surface area of the as-synthesized mesoporous nanosized doped TiO2 exceeded 460m2/g, and that of the samples after calcination at 500℃ still have 243m2/g. Compared with undoped sample and P25, the lanthana-doped mesoporous TiO2 nanoparticles show better activities on the oxidation of rhodamine B (RB). The large surface area and more active sites for combining with RB due to the present of lanthanum ion can explain the high photocatalytic activity of lanthana-doped mesoporous TiO2 nanoparticles.