Preparation of low temperature nano-structured ZnO and RhO2 on titanium substrates, and evaluation for phenol electro-catalytic oxidation

摘要

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 voltam-metry (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.