Titanium Based Materials for High-Temperature Gas Sensor in Harsh Environment Application

Gas selective sensors that are capable of sensing at hot-gas environment are increasingly gaining importance for the monitoring of combustion and thermal processes releasing NO, NO2 and H2 containing hot gases at temperatures exceeding 600 °C. Despite some drawbacks, TiO2 is capable of operating as a gas sensor above 500 °C. In this context, Ni-doped TiO2, Co-doped TiO2 and Rh-doped BaTiO3 have been prepared by oxalate coprecipitation route and fully characterized. Co-doping of TiO2 promotes p-type behavior exhibiting good sensing properties to NO2 while Ni-doping displays the maintenance of n-type behavior and better H2-sensing properties at 600 °C. Rh-doped BaTiO3 shows excellent NO sensing properties at 900 °C.

Physical Properties of Screen-Printed Polycrystalline Cadmium Sulphide Films for Solar Cells

In the present work Cadmium sulphide (CdS) nanopowder was synthesized by chemical coprecipitation route and films were synthesized by non-vacuum based and cost feasible screen-coating route. Most favorable conditions for synthesis of good quality screen-coating films were obtained. Deposited CdS films were investigated by XRD, FESEM, EDAX, UV-vis and two probes methods for microstructural, morphological, elemental, optical and electrical properties. The XRD studies reveals that the films have polycrystalline nature showing hexagonal structure with preferred orientation of grains along (002) plane for powder & (101) plane for CdS film. The morphological analysis showed the films are homogeneous with nearly spherical clusters. Elemental analysis confirmed the existence of Cd and S elements in the films with Cd/S ratio is 0.74. The optical properties of the films were investigated through absorbance & transmittance measurement. The optical direct band gap value was found to be 2.34 eV. The electrical studies revealed the semiconducting nature of CdS films with electrical resistivity in the order of 105 Ωcm and activation energy 0.4 eV.

Ni Substituted MgMn Nanoferrites as Antibacterial Agent for Biotextile Application

Biological aspects of nanoferrite incorporation is growing in demand in textile industries. In this regard the present study focuses on the synthesis of nanoferrite with Nickel substitution by Coprecipitation route. Structural studies of the nanoferrites was analyzed using X-ray diffraction. The chemical analyses determined by TEM, was in good agreement with that of XRD analysis. Thermal analysis by TG/DTA inferred that nanoferrites were thermally stable due to Ni dopants added with the compounds. MgMnNiFe2O4 nanoferrites on cotton fabrics was subjected antibacterial assay on various pathogenic microorganism and exhibits the zone of inhibition. The fabricated nanoferrites on cotton fabrics showed great durability evidenced by their antibacterial activities even after 20 washing cycles. Hence, the functionalized cotton fabrics could be used as a potential antibacterial agent.

Optically Stimulated Nanodosimeters with High Storage Capacity

In this work we report on the thermoluminescence (TL) and optically stimulated luminescence (OSL) properties of β-Na(Gd,Lu)F4:Tb3+ nanophosphors prepared via a standard high-temperature coprecipitation route. Irradiating this phosphor with X-rays not only produces radioluminescence but also leads to a bright green afterglow that is detectable up to hours after excitation has stopped. The storage capacity of the phosphor was found to be (2.83 ± 0.05) × 1016 photons/gram, which is extraordinarily high for nano-sized particles and comparable to the benchmark bulk phosphor SrAl2O4:Eu2+,Dy3+. By combining TL with OSL, we show that the relatively shallow traps, which dominate the TL glow curves and are responsible for the bright afterglow, can also be emptied optically using 808 or 980 nm infrared light while the deeper traps can only be emptied thermally. This OSL at therapeutically relevant radiation doses is of high interest to the medical dosimetry community, and is demonstrated here in uniform, solution-processable nanocrystals.

Investigation of Structural and Antifungal Behaviors of Nano-Sized Anatase Titanium Dioxide Synthesized by Co-Precipitation Route

Nowadays, the application of nano-sized anatase titanium dioxide particles becomes one of the essential research focuses by many experts, especially for biomedical applications. In this work, we report the utilization of coprecipitation route in preparing nano-sized anatase titanium dioxide as an antifungal agent. The data analysis for the XRD data of the titanium dioxide particles showed that the sample crystallized with anatase structure and sized in the nanometric size of 13.30 nm. The particle size obtained from Scherrer’s analysis of the XRD data was quite similar to the particle size obtained from electron microscopy investigation. Furthermore, the small-angle scattering data presented that the anatase titanium dioxide constructed a 3-dimensional structure with a compact structure originating from the fractal dimension value of approximately 3. The functional groups of the nano-sized anatase titanium dioxide were traced in the wavelength range of 500-1500 cm-1 showing the presence of Ti-O bonding. Interestingly, the prepared sample in this experiment exhibited an excellent performance as an antifungal agent represented by inhibition zone diameter of 3.59 mm.