[en] TiO_2 thin films prepared by sol–gel synthesis were N-doped by post treating with liquid ammonia and annealing at 500 °C. Characterisation by X-ray diffraction and Raman spectroscopy confirmed that the anatase crystal type was retained and present in all samples. Scanning electron microscopy showed that treatment with liquid ammonia had no significant effect on the film morphology. Functional testing under filtered while light conditions involving water contact angle, and the photo destruction of both Resazurin and Stearic acid showed the ammonia treated samples to be active visible light photocatalysts in contrast to the pure TiO_2 and the blank controls. X-ray Photoelectron Spectroscopy studies indicate the presence of interstitial nitrogen (N_1_s = 400 eV) suggesting that the origin of the enhanced photocatalytic activity is most likely due to oxygen vacancies created by the interstitial nitrogen incorporation. This synthesis method utilises a simple, inexpensive and highly effective post treatment route to N-dope TiO_2 and produces visible light photocatalysts with potential applications in self-cleaning and healthcare environments. - Highlights: • Synthesis and characterisation of N-doped TiO_2 thin films • N-doping by a post treatment with liquid ammonia • Enhanced photocatalytic activity • Easy enhancement of current TiO_2 based technologies

[en] Multifunctional WO_3−x–TiO₂ composite thin films have been prepared by sol–gel synthesis and shown to be good visible light photocatalysts whilst retaining a desirable underlying blue colouration. The WO_3−x–TiO₂ composite thin films were further enhanced using silver nanoparticles synthesised in-situ on the surface from the photo-degradation of silver nitrate solution. Thin films were characterised using X-ray diffraction, Raman, Scanning electron microscopy and UV–visible spectroscopy and shown to photo degrade stearic acid, using white light λ = 420–800 nm. - Highlights: ► WO_3−X TiO₂ composite thin films were synthesised by sol–gel methods. ► Blue tinted glass is desirable for the value added glass industry. ► Silver nanoparticle island formation enhances the activity of the films. ► Blue tinted “value added” coated glass is now possible.

[en] Hybrid atmospheric pressure chemical vapour and aerosol assisted deposition via the reaction of vanadium acetylacetonate and a suspension of preformed titanium dioxide or cerium dioxide nanoparticles, led to the production of vanadium dioxide nanocomposite thin films on glass substrates. The preformed nanoparticle oxides used for the aerosol were synthesised using a continuous hydrothermal flow synthesis route involving the rapid reaction of a metal salt solution with a flow of supercritical water in a flow reactor. Multifunctional nanocomposite thin films from the hybrid deposition process were characterised using scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The functional properties of the films were evaluated using variable temperature optical measurements to assess thermochromic behaviour and methylene blue photodecolourisation experiments to assess photocatalytic activity. The tests show that the films are multifunctional in that they are thermochromic (having a large change in infra-red reflectivity upon exceeding the thermochromic transition temperature) and have significant photocatalytic activity under irradiation with 254 nm light.

[en] As a catalytic coating for alkaline electrolysis Raney Nickel is one of the most efficient materials discovered, based largely on the activity of nickel and the porosity of the alloy after leaching. This study improves the electrochemical and corrosion performance of the coating for both hydrogen and oxygen evolution in alkaline water-splitting electrolysis through the use during electrodeposition of a sacrificial stainless-steel counter electrode. Analysis using energy dispersive X-ray (EDX) and scanning electron microscopy (SEM) revealed that the although the elemental make-up is largely similar, the morphology is transformed. Through measurements of the electrochemical surface area (ECSA) after long-term intermittent ageing it was found that the surface area was increased by a factor of six. Assessments and comparisons of the electrochemical performance using 3-electrode chronopotentiometry confirm this is one of the most active bifunctional coatings known.

[en] Two series of composite thin films were deposited on glass by aerosol assisted chemical vapour deposition (AACVD)-nanoparticulate cerium dioxide and nanoparticulate cerium dioxide embedded in a titanium dioxide matrix. The films were analysed by a range of techniques including UV-visible absorption spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive analysis by X-rays. The AACVD prepared films showed the functional properties of photocatalysis and super-hydrophilicity. The CeO₂ nanoparticle thin films displaying photocatalysis and photo-induced hydrophilicity almost comparable to that of anatase titania.

[en] Nano-sized particles of spinel LiMn₂O₄ and LiCr_xMn_2-xO₄ (x = Cr; 0.00-0.40) have been synthesized using phthalic acid as chelating agent for the first time by sol-gel method. When compared to solid-state synthesis method, the sol-gel route reduces heating time of synthesize and to obtain particles of uniform surface morphology. The synthesized samples were characterized through thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM images of the parent compounds show nanospherical grains of LiMn₂O₄ when compared to chromium-doped ones. XRD patterns of LiMn₂O₄ ascertain amorphous nature and for high calcined LiCr_xMn_2-xO₄ single phase highly crystalline patterns were obtained. TEM images of the parent and chromium-doped spinel particles depict individual grain morphology with well-separated grain boundaries. LiCr_0.10Mn_1.90O₄ excels in discharge and cycling behaviour and offer higher columbic efficiency, when compared to un-doped LiMn₂O₄. Cyclic voltammograms of LiMn₂O₄ and LiCr_xMn_2-xO₄ exhibit oxidation and reduction peaks corresponding to Mn³⁺/Mn⁴⁺ and Cr³⁺/Cr⁴⁺

[en] Ni-Ti alloy due to its unique mechanical properties, is used for many types of implants. Failure of these implants can be attributed to many different factors; however infections are a common problem. In this paper, the attachment of the bacteria, Staphylococcus aureus, to the Ni-Ti surface modified by a range of processes with and without of light activation (used to elicit antimicrobial properties of materials) was assessed and related to different surface characteristics. Before the light activation the number of bacterial colony forming units was the greatest for the samples thermally oxidised at 600 deg. C. This sample and the spark oxidised samples showed the highest photocatalytic activity but only the thermally oxidised samples at 600 deg. C showed a significant drop of S. aureus attachment. The findings in this study indicate that light activation and treating samples at 600 deg. C is a promising method for Ni-Ti implant applications with inherent antimicrobial properties. Light activation was shown to be an effective way to trigger photocatalytic reactions on samples covered with relatively thick titanium dioxide via accumulation of photons in the surface and a possible increase in defects which may result in free oxygen. Moreover, light activation caused an increase in the total surface energy.