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The objective of the current research was mainly focused on synthesizing the Reduced Graphene Oxide (RGO) using modified Hummers method and ZnO functionalized reduced graphene oxide (RGO) composite was fabricated by a one-pot approach. The ZnO functionalized graphene nanosheets were characterized by X-ray diffractometer (XRD) and surface morphology was examined using Transmission Electron Microscopy (TEM). Electrochemical characteristics of the ZnO/RGO composite were investigated through cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The composite was capable of delivering a high specific capacitance with excellent cycling stability. The ZnO decorated RGO catalyst was also applied to degrade different nonvolatile compounds such as Methyl Blue (MB) and Indigo carmine (IC). The performance of RGO/ZnO shows rapid degradation of dyes of high concentrations.

The objective of the existing research was essentially focused on recovery of MnO 2 nanoparticles from consumed dry cells by employing adapted hydrometallurgical process. Experimental tests for the recovery of MnO 2 present in the dry cell batteries have been carried out by an acidic reductive leachant, namely oxalic acid. The elemental compositions of the recovered metals from dry cells were confirmed by Energy Dispersive X-ray analysis (EDAX). Surface morphology of the recovered metals was examined using Scanning Electron Microscopy (SEM). Phase composition of the recovered metals from dry cell batteries were confirmed from X-ray Diffract meter (XRD). Cyclic Voltammetry (CV) studies were carried out to clarify the reversibility of the reactions. The obtained MnO 2 catalyst was applied for the degradation of different non-volatile dye compounds such as Indigo carmine (IC) and Rhodamine B (RB). The performance of MnO 2 shows fast degradation of dyes of high concentration.

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The heat transfer characteristics of nanofluid produced by mixing nano titania with transformer oil, facilitated by addition of surfactants are analyzed. A 2D model is used to analyze the heat transfer and fluid flow characteristics of nano fluid for understanding the formation of hot spots in the chamber filled with nanofluid. Governing equations for conservation of mass, momentum and energy for capturing the above characteristics are described. The temperature along the vertical mid line from the hot spot are measured experimentally and compared with simulation results. Temperature distribution obtained for nanofluid and transformer oil under both steady and transient state has revealed high rate of heat dissipation in nanofluid. Streamlines have shown the presence of press board affects flow in the bulk of the cavity. Nusselt number estimated across the edges of the hot spot has shown higher convective heat transfer in nanofluid.