No abstract

Zn-Ni-TiO 2 nanocomposites with various amounts of TiO 2 were successfully prepared by electroplating method on copper substrates using an acidic solution with TiO nanoparticles in 2 suspension. The composition and morphology of the composite coatings were characterised respectively using of scanning electron microscope (SEM), energy dispersive spectrometer and elemental mapping analysis system. The microhardness of the nanocomposite coatings was investigated. The antibacterial activity of Zn-Ni-TiO 2 nanocomposites films was studied against Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli) bacteria. Antimicrobial property increased upon the increase in the TiO 2 concentration. In addition, the antimicrobial property was more pronounced with the positive bacteria than the negative one. These results demonstrated the microbiocidal property of TiO 2 , so Zn-Ni-TiO 2 coatings have great potential applications in reducing biofouling formation in devices that suffer from biofouling problems.

No abstract

Since the dynamics of carriers are significant for a variety of applications, such as catalytic reactions, we studied the linewidth of quasiparticles for the photo-excited carriers in rutile and anatase pseudomorphs in the non-equilibrium regimes by means of many-body perturbation theory using the so-called dynamically screened interaction (GW approximation) as a method of choice. Furthermore, the influences of the commensurate electric field on the lifetime of quasiparticles are investigated through the Stark effect. The behavior of quasiparticle lifetimes qualitatively adjusts to Fermi-liquid approximation. Self-energies analysis shows that the lifetimes of excited electrons are smaller than holes for both rutile and anatase, which are in good agreement with available experiments. Likewise, the lifetimes of carriers for intraband transitions in anatase are longer than the rutile phase because of dense states near the band edges. Our results of inelastic scattering rates suggest that holes have the leading role in catalytic reactions than the electrons. Eventually, it is argued that applying an electric field will increase the decay rate, thus reducing the carrier lifetime and leading to loss of reactivity performance.

In this paper, Mn-TiO 2 nanocomposite films were successfully fabricated by the anodising of pure titanium plates in a non-aqueous electrolyte solution containing manganese ions. For the first time, potassium permanganate was used as the Mn source in anodising process. The morphology, structure and composition of these nanocomposite films were characterised by scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, elemental mapping and UV-Vis absorption spectrum respectively. Characterisation of the as prepared films indicated that potassium permanganate concentration in anodising solution significantly influenced the morphology of the surface, structure and photocatalytic activity of these films. So, to access a specific morphology, a proper concentration of KMnO 4 is required. Photocatalytic activity of samples was evaluated by testing the water splitting. The Mn-TiO 2 -1 nanocomposite exhibited better photocatalytic activity than did the bare TiO 2 film and other Mn-TiO 2 nanocomposites.