Preparation of low temperature nano-structured ZnO and RhO2 on titanium substrates, and evaluation for phenol electro-catalytic oxidation
Faculty of Science, School of Chemistry, University of the Witwatersrand, Private Bag 3, Johannesburg 2050, South Africa
Klink, M.J., Faculty of Science, School of Chemistry, University of the Witwatersrand, Private Bag 3, Johannesburg 2050, South Africa; Crouch, A.M., Faculty of Science, School of Chemistry, University of the Witwatersrand, Private Bag 3, Johannesburg 2050, South Africa
An approach based on a thermodynamical growth control concept of ZnO and RhO2 nano-structured metal oxides on a titanium substrate for electro-catalytic oxidation of phenol is demonstrated. These nano-structured metal oxide materials prepared via a low temperature thin film growth technique were characterized by scanning electron microscopy. The effect of the method employed, i.e. three-dimensional arrays, could be clearly seen in the estimated values of surface roughness. The scanning electron technique confirmed the sizes of the metal titanium oxide materials in the nano range: The diameter of the ZnO rods ranges from 50-150 nanometers and the lengths from 1-2 μm. The diameters of RhO2 showed oval structures from 10-100 nanometers. Thermogravimetric analyses showed that at 450 °C and 800 °C (the calcination temperature) no further structural changes occurred due to mass loss for ZnO and RhO2 respectively. Cyclic voltammetry (CV) showed that both the Ti/ZnO and Ti/RhO2 nano-structured electrodes can be used for phenol electro-catalytic oxidation and that the Ti/RhO2 electrode can also be used as a sensor for the detection of phenol. © Springer-Verlag 2009.
Cyclic voltammetry (CV); Metal oxide nano-structures; Scanning electron microscopy (SEM); Thermal Gravimetric Analysis (TGA)