We report the synthesis and photoelectrochemical assessment of phase pure tetragonal matlockite structured BiOX (where X = Cl, Br, I) films.

The Joule heating properties of an ultralight nanocarbon aerogel are investigated with a view to potential applications as energy-efficient, local gas heater and other systems. Thermallyreduced graphene oxide (rGO) aerogels (10 mg cm -3 ) with defined shape are produced via emulsion-templating. Relevant material properties, including thermal conductivity, electrical conductivity and porosity, are assessed. Repeatable Joule heating up to 200°C at comparatively low voltages (~ 1V) and electrical power inputs (~2.5 W cm -3 ) is demonstrated.The steady-state core and surface temperatures are measured, analyzed and compared to analogous two-dimensional nanocarbon film heaters. The assessment of temperature uniformity suggests that heat losses are dominated by conductive and convective heat dissipation at the temperature range studied. The radial temperature gradient of an uninsulated, Joule-heated sample is analyzed to estimate the aerogel's thermal conductivity (around 0.4 W m -1 K -1 ). Fast initial Joule heating kinetics and cooling rates (up to 10 K s -1 )were exploited for rapid and repeatable temperature cycling, important for potential 2 applications in catalysis and for the thermal regeneration of solid adsorbers. These principles may be relevant to wide range of nanocarbon networks and applications.

This paper reports the synthesis of highly conductive niobium doped titanium dioxide (Nb:TiO 2 ) fi lms from the decomposition of Ti(OEt) 4 with dopant quantities of Nb(OEt) 5 by aerosol-assisted chemical vapor deposition (AACVD). Doping Nb into the Ti sites results in n -type conductivity, as determined by Hall effect measurements. The doped fi lms display signifi cantly improved electrical properties compared to pristine TiO 2 fi lms. For 5 at.% Nb in the fi lms, the charge carrier concentration was 2 × 10 21 cm −3 with a mobility of 2 cm 2 V -1 s -1 . The corresponding sheet resistance is as low as 6.5 Ω sq -1 making the fi lms suitable candidates for transparent conducting oxide (TCO) materials. This is, to the best of our knowledge, the lowest reported sheet resistance for Nb:TiO 2 fi lms synthesized by vapour deposition. The doped fi lms are also blue in colour, with the intensity dependent on the Nb concentration in the fi lms. A combination of synchrotron, laboratory and theoretical techniques confi rmed niobium doping into the anatase TiO 2 lattice. Computational methods also confi rmed experimental results of both delocalized (Ti 4+ ) and localized polaronic states (Ti 3+ ) states. Additionally, the doped fi lms also functioned as photocatalysts. Thus, Nb:TiO 2 combines four functional properties (photocatalysis, electrical conductivity, optical transparency and blue colouration) within the same layer, making it a promising alternative to conventional TCO materials.

Aerosol assisted chemical vapour deposition (AACVD) was used to synthesise a TiO 2 -SnO 2 composite film onto a glass substrate. For comparison a TiO 2 film and a SnO 2 film were also prepared. All films were characterised by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and wavelength dispersive X-ray spectroscopy (WDX). XPS and WDX of the composite film revealed a TiO 2 rich film with a high level of SnO 2 segregation at the surface. Highly structured pyramid-like features gave rise to hydrophobic films with static water contact angles of 134 .Photocatalytic activities were determined by monitoring the degradation of intelligent ink (containing Resazurin redox dye) via UV-visible spectroscopy. Under UVA irradiation, the TiO 2 film only began to degrade the dye after being irradiated in excess of 100 minutes, whereas the composite TiO 2 -SnO 2 film required only 6 minutes of irradiation before degradation was observed. The formal quantum efficiency (FQE) for the TiO 2 -SnO 2 composite was determined to be 1.01 Â 10 À2 molecules per incident photon and the formal quantum yield (FQY) was 1.17 Â 10 À2 molecules per absorbed photon. This is an order of magnitude superior to Pilkington ActivÔ self-cleaning glass a commercial self-cleaning TiO 2 coating on glass. This improved photocatalytic activity is attributed to the presence of electron scavenging SnO 2 sites that increase charge separation and the increased surface area due to the highly structured morphology.