Susuz Ortamda Tiox Filmlerinin Elektrokimyasal Olarak Hazırlanması ve Karakterizasyonu

Abstract

Titanium tends to form many different compounds with oxygen in its crystalline form, such as TiO2 and Ti2O3, Ti3O5 and TinO2n-1 (4<n<10) (named TiOx). Among these, TiO2 is preferred in most studies, due to being thermodynamically stable in the atmospheric conditions, being inexpensive and non-toxic. Another form of titanium oxide compounds is known as Magnéli phase with the formula TinO2n-1 (4<n<10), which has high electrical conductivity and chemical stability. According to the studies in the literature, Magnéli phase compounds are derived by heating TiO2 with titanium metal powder under inert atmosphere or by heating TiO2 in the presence of hydrogen gas (as reducing agent) at high temperatures. TiO2 is used as the main feedstock due to its abudance and relatively low cost. Usually in these methods, high temperature (>1273 K) and reducing atmosphere (e.g. H2 gas) are required. In the literature, there are studies which are in aqueous media and require high temperatures. The aim of this study, contrary to the studies in the literature, is the electrochemical deposition of TiOx films for the first time in nonaqueous media without requiring high temperatures. For this purpose, it is demonstrated that the reduction of formed titanium hydroxide hydrate compounds is possible in the presence of acetonitrile. After determining optimal conditions for TiOx electrochemical synthesis, films which deposited on the electrode surface were characterized by using X-ray diffractometry, UV-Vis spectroscopy, Raman Spectroscopy and Scanning electron microscopy (SEM). TiO2 is used widely as a semi-conductive material in dye-synthesized solar cells. In this study, TiOx films with lower band gap than to TiO2 was obtained. TiOx is also a semi-conductive material that can absorb in the visible light range unlike TiO2. In this study, photocurrent density of Dye-sensitized solar cells that constructed with TiOx layer or TiOx-TiO2 bilayer measured and photovoltaic behaviors were investigated.