Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Kimya Bölümü, Türkiye
Tezin Onay Tarihi: 2017
Öğrenci: ELİF DEMİR
Danışman: AHMET MUHTAR ÖNAL
Özet:In this study, Ru0/MO2 catalysts were prepared by reduction of ruthenium(III) chloride on different types of metal oxides, which were TiO2, ZrO2, CeO2 and HfO2, then catalysts were loaded on glassy carbon (GC) electrodes at same mass loading level, and used as electrocatalysts in 0.5 M H2SO4 solution for hydrogen evolution reaction (HER). Characterization of prepared catalysts were done by using transmission electron microscopy (TEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD) spectroscopy and X-ray photoelectron spectroscopy (XPS), also, loading level of these catalysts were investigated by using inductively coupled plasma-optical emission spectrometry (ICP-OES). Electrochemical behavior of the modified glassy carbon electrodes and their electrocatalytic activity towards the hydrogen evolution during water electrolysis was investigated in acidic solution (0.5 M H2SO4) at room temperature by linear sweep voltammetry (LSV), cyclic voltammetry (CV), potentiostatic electrochemical impedance spectroscopy (EIS) and constant potential electrolysis. Among the Ru0/MO2 modified GC electrodes, Ru0/CeO2 modified GCE was found to be better for HER in terms of onset potentials, current density at a defined overpotential, exchange current densities and Tafel slopes. To investigate the amount of Ruthenium on the electrocatalytic effect, different loading levels of Ru0/CeO2-GC electrodes were prepared and analyzed towards hydrogen evolution reaction during water electrolysis. The glassy carbon electrode modified by Ru0/CeO2 with a ruthenium loading of 1.86% wt. provided an outstanding electrochemical activity with a high exchange current density of 0.67 mA.cm-2, low overpotential of (ɳ) 47 mV at j = 10 mA.cm−2 and small Tafel slope of 41 mV.dec-1. Furthermore, electrocatalytic activity of Ru0/MO2 modified GCEs towards the oxygen evolution during water electrolysis was investigated in 0.5 M KOH solution. Ru0/CeO2 (1.86% wt. Ru)-GC electrode was found to exhibit better electrocatalytic activity towards OER.