A study of TiO2 binder-free paste prepared for low temperature dye-sensitized solar cells

A binder-free titania paste was prepared by chemical modification of an acidic TiO2 sol with ammonia. By varying the ammonia concentration, the viscosity of the acidic TiO2 suspension increased, thereby allowing uniform films to be cast. The photoelectrochemical performance of TiO2 electrodes, cast as single layers, was dependent on the thermal treatment cycle. Fourier transform infrared spectroscopy was used to characterize the extent of residual organics and found that acetates from the TiO2 precursor preparation were retained within the electrode structure after thermal treatment at 150 °C. Electrodes of nominal thickness 4 lm produced an energy conversion efficiency as high as 5.4% using this simple thermal treatment

Porous ZrC-carbon microspheres as potential insoluble target matrices for production of\u3csup\u3e188\u3c/sup\u3eW/\u3csup\u3e188\u3c/sup\u3eRe

New microsphere sorbents are reported, which could find application in demanding radiation environments and especially as targets for the production of nuclear medicines by neutron irradiation. An easily-synthesized Zr anionic complex was introduced into quaternary amine-functionalised polystyrene-divinylbenzene-based anion-exchange resins by batch adsorption. Upon carbothermal reduction, the precursors were converted to porous carbon matrices containing particles of ZrC and ZrO2polymorphs. The most phase-pure material, ZrAX-1, possessed high surface area, multi-scale porosity and high mechanical strength. Adsorption of Re and W was investigated and its possible deployment as a reusable host for the production of188W/188Re is discussed

Porous Zr2SC-carbon composite microspheres: Possible radiation tolerant sorbents and transmutation hosts for technetium-99

The preparation, characteristics and adsorption properties of novel porous carbon-ceramic composite microspheres are presented. The composites were synthesised by a simple ion exchange process involving the cationic Zr tetramer and commonly-available macroporous sulphonated polystyrene-divinylbenzene cation exchange resins, with subsequent carbothermal reduction at 1350 °C. The materials were extensively characterised with respect to composition, chemical structure and porosity. Carbothermal reduction of the Zr-loaded templates resulted in formation of crystallites of the MAX phase zirconium sulphide carbide (Zr 2 SC) embedded within a highly microporous carbon framework with a macroporous secondary structure inherited from the resin template. Despite the high BET surface areas of the Zr 2 SC-carbon composite microspheres (in some cases, greater than 600 m 2 g −1 ), they are extremely mechanically robust. The microspheres displayed high adsorption selectivity for oxoanions relative to cationic solution species, including perrhenate (ReO 4 − ), a pertechnetate (TcO 4 − ) surrogate. Accumulation of ReO 4 − on the Zr 2 SC particles was unequivocally demonstrated by elemental mapping. Such materials are potential candidates as combined 99 Tc sorbents and reusable transmutation hosts

Cu(II) ion directed self-assembly of a Y8/Cu6 heterometallic coordination cage via an Y(III) metalloligand

A non-centrosymmetric yttrium [Y(III)] metalloligand, [Y(H3L)(NO3)]·2NO3·THF (1) {tris{[2-{(imidazole)methylidene}amino]-ethyl}amine = H3L}, was synthesized and subsequently used in a Cu(II) directed self-assembly process to form a Y8/Cu6- type heterometallic coordination cage [Cu6Y8L8(NO3)5(H2O)3]·7NO3·21H2O (2). The eight corners of the distorted cubic cage are defined by eight Y(III) ions while Cu(II) ions occupy the centers of six faces with two opposite Cu(II) ions considerably outside the faces. The asymmetric Y(III) metal centres due to the extra coordination of either water molecules or nitrate anions induce chirality in the cage, with equal numbers of both enantiomers present in the solid state. The cage formation in both solution and in the solid state was demonstrated by ESI-MS and single crystal X-ray diffraction. Magnetic property measurements indicate that cage 2 remains paramagnetic down to 2 K. In addition, vibrational modes, electronic structure and thermal stability of the coordination cage 2 have been further investigated and reported

Synthesis and characterisation of nanocomposite materials prepared by dispersion of functional TiO2 nanoparticles in PMMA matrix

International audienc

A study of TiO 2

A binder-free titania paste was prepared by chemical modification of an acidic TiO2 sol with ammonia. By varying the ammonia concentration, the viscosity of the acidic TiO2 suspension increased, thereby allowing uniform films to be cast. The photoelectrochemical performance of TiO2 electrodes, cast as single layers, was dependent on the thermal treatment cycle. Fourier transform infrared spectroscopy was used to characterize the extent of residual organics and found that acetates from the TiO2 precursor preparation were retained within the electrode structure after thermal treatment at 150 °C. Electrodes of nominal thickness 4 lm produced an energy conversion efficiency as high as 5.4% using this simple thermal treatment