Size Dependent Gold Assisted ZnO Growth on Si Surface by Continuous Spray Pyrolysis Reactor for Light Suppression

AbstractColloidal Au particles of sizes 15 and 40nm are spray deposited on polished Si surface and then the deposition of ZnO nanostructure layer using Continuous Spray Pyrolysis reactor is performed. XRD data suggests that the larger size Au nanoparticles act as seed particles for ZnO nanostructure formation, while smaller Au nanoparticles favour (002) oriented growth. SEM measurement confirms enhancement of ZnO nanorods growth in the case of 40nm Au assisted deposition. The reflection measurement shows higher surface plasmon resonance for larger size Au particles and hence significant light reduction up to 51% of existing value in 500-900nm wavelength region is achieved which may ultimately help in the increase of photocurrent in Si solar cells

Metal nanoparticles enhanced thermophysical properties of phase change material for thermal energy storage

Phase change materials (PCMs) are one of the promising materials in thermal energy storage systems. In this work PCM nanocomposites were prepared using melt-blending technique by dispersing metal nanoparticles (Fe, Cu) at mass fraction of 0.5 wt% in magnesium nitrate hexahydrate (MNH), an inorganic salt hydrate PCM. The as-prepared PCM nanocomposites were analyzed by scanning electron microscopy (SEM) and X-ray diffractometer (XRD). Fourier transform infrared spectroscopy (FTIR) analysis was carried out to monitor the changes in chemical nature of PCM nanocomposites. The heat transfer characteristics were investigated by conventional heating system, which were used to carry out melting (charging) and solidification (discharging) cycle of MNH-metal nanocomposites. The experiment results clearly indicates that the rate of melting and solidification of MNH-metal nanocomposites increased at 0.5 wt% mass fraction of metal nanoparticles as compared to MNH. The thermal conductivity of MNH-metal nanocomposites at 0.5 wt% mass fraction of metal nanoparticles (Fe, Cu) in solid phase was measured using the transient hot method, which clearly indicates that thermal conductivity improved to (0.61) W m(-1) K-1 for MNH-Fe nanocomposite & (0.63) W m(-1) K-1 for MNH-Cu nanocomposite than that of pure MNH (0.4) W m(-1) K-1. The prepared nanocomposites showed good heat transfer characteristics and better thermal conductivity. Therefore, this study demonstrates that metal nanoparticles, added to inorganic PCM (MNH) had a significant potential for enhancing the thermophysical properties and makes it promising candidate for thermal energy application