New chemical synthetic route for the fabrication of metal oxide nanostructures and their structural, optical, electrical and electrochemical properties are presented. Chemical solution deposition method was used to control the phase and crytallinity by varying the growth temperature and time. Detailed characterizations of the crystal structure, chemical composition, and morphology of the as-synthesized products were carried out using adequate techniques. The mechanism governing the direct growth of oxide nanostructures on conducting and insulating substrates is studied. Field emission, electrochemical and photocatalytic properties of as-synthesized nanostructures are described in this work. This study reveals the excellent photocatalytic, electrochemical and field emission properties of vanadates nanowires with fairly low turn-on field and high current emission capability.

The nanostructures of transition metal oxides have gained considerable attention for energy storage devices as they can deliver high levels of electrical power and offer long operating lifetimes, but their specific capacitance is too low for many important applications. The poor conductivity of metal oxides limits the charge/discharge rate for high energy/power densities and the specific capacitance severely decreases under high current. In this book we proposed a simple and an efficient method to improve the conductivity of metal oxide nanowires based electrodes by interweaving nanowires with MWCNTs to form hybrid energy storage devices which allow fast electron transport, fast ion diffusion and high-energy storage densities. In addition MWCNTs can accommodate large strain without pulverization, provide good electronic contact and conduction, display short ions insertion distances and make them promising candidates as electrodes in high-performance energy storage devices.