Sharif Digital Repository

Local photodegradation of graphene oxide sheets at the tip of ZnO nanorods was used to achieve semiconducting graphene nanomeshes. The chemically exfoliated graphene oxide sheets, with a thickness of ∼0.9 nm, were deposited on quartz substrates. Vertically aligned ZnO nanorod arrays with diameters of 140 nm and lengths of <1 μm were grown on a glass substrate by using a hydrothermal method. The graphene oxide sheets were physically attached to the tip of the ZnO nanorods by assembling the sheets on the nanorods. UV-assisted photodegradation of the graphene oxide sheets (with dimension of ∼5 × 5 μm) at a contact place with the ZnO nanorods resulted in graphene nanomeshes with a pore size of... 

Charge-discharge rate capability is one of the most important properties of cathode materials for lithium batteries, in particular when envisaging high power density applications such as automotive applications. Efforts to modify rate have been carried out by carbon coating and decreasing particle size in order to modify electronic and ionic conductivity. However, this approach cannot justify all experimental data reported in the literature. Here, we investigated the rate capability of cathode materials by considering their density of states (DOS) calculated by several density functional theory (DFT) methods, in both the lithiated and the delithiated case. We suggested that these structures... 

Semiconducting lead sulfide film was deposited on Stainless Steel (SS) electrode by cyclic voltammetry (CV) at room temperature. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry were used to investigate the electrochemical properties of PbS film in Na2SO4 solution. The voltammetric results showed that oxidative dissolution of PbS film occurred at about 0.21 V vs. Ag/AgCl and total film detachment from the surface occurs with increasing potential. It is concluded that the electrode surface was not passivated by sulfur produced from oxidative dissolution of PbS film. Also, cathodic reduction of the film continued to beyond the hydrogen evolution at -1.35 V vs. Ag/AgCl....