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The photoreduction of NO3 − and NO2 − was performed at 60 °C under irradiation of visible light (λ > 400 nm) in the presence of unsupported CdS, H4Nb6O17/CdS and H2Ti4O9/CdS in 10 vol.% aqueous methanol solution. The photoreduction rate of NO3 − proceeded in the presence of H4Nb6O17/CdS and H2Ti4O9/CdS nanocomposites although unsupported CdS, H4Nb6O17/CdS and H2Ti4O9/CdS did not show photocatalytic activity for nitrate reduction under visible light irradiation. The photoreduction rate of NO3 − and NO2 − changed significantly depending on solution pH, i.e., with increasing solution pH the reduction rate of NO3 − increased, on the orther hand, that of NO2 − decreased.

TiO 2 and Pt have been intercalated in hectorite and H 4 Nb 6 O 17 . The height of TiO 2 and Pt pillars was less than 0.8 nm and the band gap energy of TiO 2 pillars was ca. 3.3 eV. Both hectorite/TiO 2 and H 4 Nb 6 O 17 /(Pt,TiO 2 ) were capable of hydrogen evolution following irradiation from a high pressure mercury arc (λ > 290 nm) in the presence of methanol as a sacrificial hole acceptor and the hydrogen evolution was enhanced by co-incorporation of Pt. although hectorite and hectorite/Pt did not show photocatalytic activity. Incorporation of Pt or Pt and TiO 2 in the interlayer of H 4 Nb 6 O 17 has resulted in enhanced photo evolution of hydrogen, however, TiO 2 alone in the interlayer of H 4 Nb 6 O 17 showed adverse photocatalytic activity.

TiO 2 intercalated H 4 Nb 6 O 17 has been synthesized by the reactions of H 4 Nb 6 O 17 with a titanyl acylate complex followed by UV irradiation. The gallery height, specific surface area and Ti content of the sample synthesized by using titanyl acylate complex were larger than that using TiO 2 sol solution. Furthermore, the photocatalytic activity of the TiO 2 pillared H 4 Nb 6 O 17 prepared using a titanyl acylate precursor was twice larger than that fabricated using a TiO 2 sol solution.

The preparation and strength of a calcium phosphate based cement with and without dispersed particles of polycrystalline 12 mol-%CeO2 doped tetragonal zirconia (12Ce–TZP) were investigated. A cement mixture of α-tricalcium phosphate (α-Ca3 (PO4 )2 ) and tetracalcium phosphate (Ca4 (PO4 )2O) with a Ca/P ratio of 1·67 transformed completely to hydroxyapatite after curing under water for 7 d at 38°C. The compressive strength of a cement without dispersed 12Ce–TZP particles cured for 4 d at 38°C was ∼11·1 MPa but increased to ∼16 MPa by dispersing 3 wt-%12Ce–TZP particles, of average diameter 40 μm, which were treated in 10M NaOH and/or 0·01M Ca5 (PO4 )2 gel solutions prior to dispersion.

Normal sintering and capsule free hot isostatic pressing (HIPing) of 12CeO2–88ZrO2 powder were carried out at 1100–1200°C using different starting powders. Porous ceramics of this composition with ∼35%open porosity, micropore diameters of ∼23 nm, and narrow pore size distributions were fabricated by capsule free hot isostatic pressing at 1100°C using the powders crystallised in methanol followed by supercritical drying. The porosity increased with decrease in HIPing temperature and was accompanied by a steady decrease in fracture strength.