R.C. Pawar

Photoelectrochemical properties of CdS sensitized ZnO nanorod arrays: Effect of nanorod length

The vertically aligned ZnO nanorod arrays were achieved from aqueous chemical route on soda lime and transparent conducting oxide coated glass substrates. The length of nanorods was varied from 1.6u2009μm to 4.5u2009μm by varying deposition time. The aspect ratio of ZnO nanorod was increased with increasing deposition time. Cadmium sulfide (CdS) nanoparticles have been subjected to self-assemble onto ZnO nanorods (ZNRs) using chemical bath deposition method. The synthesized CdS/ZnO nanorod arrays were characterized for their optical, structural, and morphological properties with UV-visible absorption spectroscopy (UV-Vis), x-ray diffraction, energy-dispersive x-ray analysis, x-ray photoelectron spectroscopy, contact angle measurement, and scanning electron microscopy. The cross-section images of the samples clearly depict different lengths of ZnO nanorods. UV-vis absorption spectrum shows the significant red shifting after covering of the CdS nanoparticles over the ZnO nanorods. The lengths of ZnO nanorod arrays ...

Effect of annealing on the supercapacitor performance of CuO-PAA/CNT films

We report the synthesis of CuO-poly(acrylic) acid/CNT hybrid thin films by a cost-effective spin-coating technique for supercapacitor application. Hybrid films were annealed at 300, 400, and 500xa0°C to study its effect on the supercapacitor behavior. X-ray photoelectron spectroscopy and Fourier transform-infrared spectroscopy techniques were used for the phase identification and determination of the organic component in the hybrid films, respectively. Surface morphology of the films was examined by scanning electron microscopy and revealed the novel ring-like structures. The average diameter of the ring changes from 0.5 to 1.2xa0μm with increase in annealing temperature. Cyclic voltammetry is employed to estimate the specific capacitance (Csp) of the films in 1xa0M H2SO4 electrolyte. It is observed that the Csp increases from 188 to 258xa0Fg−1 with increase in annealing temperature.

Surfactant mediated growth of ZnO nanostructures and their dye sensitized solar cell properties

Single crystalline and highly aligned ZnO nanorods, faceted microrods, nanoneedles and nanotowers were grown onto glass substrates by a facile aqueous chemical method at relatively low temperature (90xa0°C). Various structure directing agents or organic surfactants such as diaminopropane (DAP), polyacrylic acid (PAA) and polyethylenimine (PEI) were used to modify the surface morphology. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical absorption. It was found that, vertically aligned ZnO nanorods formation takes place with preferential orientation along (002) plane. The organic surfactants play an important role in modifying the morphology. The samples were further used to fabricate dye sensitized solar cells. The highest photocurrent (670 μA) and efficiency were observed for the ZnO:PEI sample.