Sharif Digital Repository

An isopropanol supercritical reducing environment was prepared by fabricating a high temperature, high pressure autoclave, in order to make a hybridized structure of zinc oxide and graphene oxide, entitled as ZnO-G. In this novel structure, the oxygen acts as bridging element between zinc and carbon, that connects a wide band gap semiconductor to a narrow banded one. The hybridization mechanism is studied by FTIR analysis, and morphology is shown by FE-SEM. The micrographs obtained from the thin film show a stacked pile of ZnO-G disks, like a button, dispersed on a crack free layer. In addition, the crystallographic structure was revealed by comparing low angle X-ray diffraction patterns to... 

Hexavalent chromium ions (Cr(VI)) is one of the most dangerous heavy ions for the environment, humans and other living organisms. Hence, finding new ways to determine and reduction to the much less toxic trivalent chromium (Cr(III)) is highly important. In this thesis, electrochemical and photoelectrochemical methods have been employed for the direct detection and reduction of Cr (VI). For this purpose, the indium tin oxide (ITO) electrode decorated with gold-palladium bimetallic nanoparticles (AuPd) was used for the determination and reduction of Cr(VI) via electrochemical route. These AuPd decorated electrodes exhibited a wide linear concentration range of 0.001-100 µM, a very low... 

In this study, one dimensional titanium dioxide nanostructures including nanotube and nanowire were synthesized by anodization and hydrothermal methods respectively and were used for PEC glucose sensing. Meanwhile various length of nanotubes was investigated toward glucose sensing. Finally, nanotubes with the length of 2.7 µm were selected as the optimum sample. Finally, to improve sensitivity toward glucose, TiO2 nanotubes were modified by graphene oxide nanosheets which caused several percent increase in PEC sensing performances. In the next stage branched TiO2 nanowires were grew on FTO substrate in various conditions. In spite of acceptable reproducibility of this structure,...