Enhanced photocatalytic performance and impact of annealing temperature on TiO2/Gd2O3:Fe composite

Journal of Materials Science: Materials in Electronics - This work relates to an experimental study concerning the elaboration of the composite material TiO2/Gd2O3:Fe (TiO–Gd:Fe) from powders...     

Facile Synthesis and Antibacterial Activity of Bioplastic Membrane Containing In Doped ZnO/Cellulose Acetate Nanocomposite

The present work addresses a facile synthesis of Indium doped zinc oxide (IZO) cellulose acetate nanocomposite membrane. The membrane was prepared by casting method. Various weights of In:ZnO nanoparticles were added to solution formed by dissolution of cellulose acetate granules in acetone. The harvested membrane, after acetone evaporation, was characterized by various techniques including X ray diffraction, scanning electron microscopy, energy dispersive X ray and elemental mapping, Fourier transform infrared spectroscopy. The results show that the In:ZnO nanoparticles are well embedded in the cellulose acetate host matrix. The elemental mapping reveals that the nanoparticles are uniformly distributed. The optical characterization reveals the reduction of the transmittance in the UV (A and B range) of the CA/IZO composite with increasing the weight of the added IZO powder. This reduction was attributed to ZnO UV absorption. No noticeable peak assigned to ZnO bond are observed. However, IR peaks are shifted towards the higher wavenumber due to the change of the bonds environment with including IZO in the CA matrix. The antibacterial action of the synthetized nanocomposite membranes was tested against Escherichia coli (E. coli). Staphylococcus aureus (S. aureus). The assay results have shown that the membrane has no activity against (E. coli). In contrary, the synthetized membrane exhibits an interesting antibacterial activity against S. aureus. The inhibition region varies from 6 to 15 mm with increasing the weight ratio of filler. A zone of inhibition (ZOI) of 18 mm was observed for the membrane prepared with 30% wt. of In:ZnO. We noticed that the ZOI radius increases with the added weight of IZO. Due the settling down of the nanoparticles only one face of the membrane exhibits an antibacterial activity.

     

Comparative study of multilayered ZnO/TiO<Subscript>2</Subscript>/ZnO and TiO<Subscript>2</Subscript>/ZnO/TiO<Subscript>2</Subscript> thin films prepared by sol–gel dip coating method

The aim of this research work is to represent the comparative study of ZnO/TiO₂/ZnO (ZTZ) and TiO₂/ZnO/TiO₂ (TZT) thin films deposited by sol–gel dip coating on FTO substrates. After deposition, the films were annealed at 500 °C for 1 h. Structural, surface morphology, optical and electrical properties of these films were studied by X-ray diffractrometer (XRD), Raman spectra, atomic force microscope (AFM), photoluminescence spectra (PL) and four point probe technique respectively. XRD and Raman spectra confirmed the anatase, brookite phases of TiO₂ and cubic phase of ZnO. AFM confirmed the formation of nano particles with average sizes of 18.4 and 47.2 nm of TZT and ZTZ films respectively. According to PL spectra, both the multilayer films slowdown the electron hole recombination rate and enhances the optoelectronic properties of the materials. Also it showed the peaks in the visible region of spectrum. The four point probe results showed that the average sheet resistivity of the films is 450 and 120 (ohm-m) respectively.