R. Gobi

Synthesis and characterization of surfactants assisted Cu2+ doped ZnO nanocrystals

In the present work, we report a simple chemical precipitation method to synthesize precursors of different levels of Cu(2+) ions doped crystalline zinc oxide (ZnO) nanoparticles in the presence of capping agents namely cetyltrimethyl ammonium bromide (CTAB) and sodium hexametaphosphate (SHMP). Thermal analysis result suggests that 300°C could be the optimum level of annealing for the harvest of pure phase of ZnO from the as prepared particles. The structural, optical and chemical features of undoped and surfactants assisted ZnO: Cu(2+) nanoparticles were studied by X-ray powder diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-Visible (UV-Vis) absorption spectroscopy and photoluminescence (PL) measurements. Among the two surfactants used SHMP is an effective one in controlling the size and morphology of the particles.

Synthesis and characterization of ZrO2-CuO co-doped ceria nanoparticles via chemical precipitation method.

In the present study, the fluorite cubic phase of bare and ZrO2-CuO co-doped ceria (CeO2) nanoparticles have been synthesized through a simple chemical precipitation method. X-ray diffraction results revealed that average grain sizes of the samples are within 5-6nm range. The functional groups present in the samples were identified by Fourier Transform Infrared Spectroscopy (FTIR) study. Surface area measurement was carried out for the ceria nanoparticles to characterize the surface properties of the synthesized samples. The direct optical cutoff wavelength from DRS analysis was blue-shifted evidently with respect to the bulk material and indicated quantum-size confinement effect in the nanocrystallites. PL spectra revealed the strong and sharp UV emission at 401nm. The surface morphology and the element constitution of the pure and doped nanoparticles were studied by scanning electron microscope fitted with energy dispersive X-ray spectrometer arrangement. The thermal decomposition course was followed using thermo gravimetric and differential thermal analyses (TG-DTA).

Preparation, structural and morphological studies of Ni doped titania nanoparticles.

TiO2 nanoparticles doped with different weight percentages (4%, 8%, 12% and 16%) of nickel contents were prepared by a modified sol-gel method using Titanium tetra iso propoxide and nickel nitrate as precursors and 2-propanol as a solvent. X-ray diffraction studies show that the as prepared and annealed products show anatase structure with average particle sizes running between of 8 and 16 nm. FTIR results demonstrate the presence of strong chemical bonding at the interface of TiO2 nanoparticles. The optical properties of bare and doped samples were carried out using UV-DRS and photoluminescence measurements. The surface morphology and the element constitution of the nickel doped TiO2 nanoparticles were studied by scanning electron microscope attached with energy dispersive X-ray spectrometer arrangement. The non linear optical properties of the products were confirmed by Kurtz second harmonic generation (SHG) test and the output power generated by the nanoparticle was compared with that of potassium di hydrogen phosphate (KDP).

Synthesis and characterization of Ni2+ ions incorporated CuO nanoparticles and its application in antibacterial activity

In this present work, Ni doped CuO nanoparticles were successfully prepared by chemical precipitation method. The structural and chemical compositions of the products were characterized by X-ray diffraction, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The obtained products were identified to be of monoclinic structure and these results demonstrate that the Ni ions were substituted into the CuO lattice. The optical properties of the products were studied by diffuse reflectance spectroscopy and room temperature photoluminescence measurements. The morphological analyses were obtained by using field emission scanning electron microscopy and transmission electron microscopy. The magnetic properties were investigated at room temperature using the vibrating sample magnetometer and the hysteresis loops confirmed the ferromagnetic behaviour of CuO on doping due to smaller size effect. Further, as-formed doped and undoped CuO nanoparticles exhibit significant antibacterial activity against pathogenic bacterial strains namely Gram −ve (Pseudomonas aeruginosa, and Escherichia coli), Gram +ve bacteria (Bacillus subtilis, Staphylococcus aureus).

Investigation on the structural, optical, morphological and magnetic properties of undoped and Cd doped CuO nanoflakes

Presented here is the cadmium doped CuO nanoflakes prepared via a simple chemical precipitation method at room temperature. The results of X-ray line broadening exhibit the crystalline nature of the prepared products. X-ray photoelectron spectroscopy showed the bivalent nature of copper. The functional groups of the samples were identified by Fourier transform infrared spectroscopy. UV–Visible absorption and photoluminescence measurements reveal the optical properties of the products. The formation of CuO nanoflakes can be seen by field emission scanning electron microscopy and confirmed by transmission electron microscopy. The susceptibility measurements show the enhanced ferromagnetic behaviour of CuO with the cadmium doping.