Sharif Digital Repository

Vertical copper oxide nanoflakes were synthesized on a Cu foil through oxidation in alkaline conditions. X-ray photoelectron spectroscopy showed that after exposing the nanoflakes to an Escherichia coli bacterial suspension, the outermost surface of the nanoflakes was chemically reduced through the glycolysis process of the bacteria. Current-voltage (I-V) characteristics of the nanoflakes (measured perpendicular to surface of the Cu foil by using conductive atomic force microscopy) indicated that electrical resistivity of the nanoflakes increased about one order of magnitude after exposure to the bacterial suspension. The nanoflakes reduced by the bacterial suspension could also be... 

In this work, a comparative study has been performed on two ex-situ and one in-situ doping of titania photoanodes with reduced graphene oxide. The presence of finely dispersed reduced graphene oxide facilitates electron transport and reduces electron-hole recombination resulting in a better performance of doped titania photoanodes. It was found that in-situ doping, i.e. introduction of graphene oxide in solution together with titania precursor was the most performant case of graphene doping. This result was obvious by studying dye-sensitized solar cells based on such doped photoanodes but was also and mainly analytically demonstrated by subjecting the obtained materials to characterization...