Eletrodos de nanotubos de TiO2: uma ferramenta poderosa no tratamento ambiental, eletroanálise, desinfecção de água, produção de hidrogênio e conversão de CO2

The great versatility of TiO2 as semiconductor materials and the possibility of electrons, holes, hydroxyl radicals and/or superoxide radical’s generation has increased their applicability as catalyst. Electrodes based on self- organized nanotubes of Ti/TiO2 is one of the most studied compounds in materials science and easy to grow by electrochemical methods. Special attention will be focused on the applications of TiO2 and the modification of its surface at nanoscale architectures, with great improvement of the electrocatalyst properties useful for degradation of organic pollutants, reduction of inorganic contaminants, microorganism inactivation, development of electrochemical sensors, CO2 reduction and hydrogen production with great success. In order to improve the power of the technique we have developed several types of semiconductor nanostructured based on TiO2 with and without decoration with nanoparticles of Pt, Ag, B, Sb2S3, complex of copper aspirinate, MOF and composites of TiO2/WO3 and Si/TiO2 decorated with Pt or Au and combined processes. They were applied successful in photoelectrocatalytic reactors with great enhance in the efficiency of: i) micropollutant contaminants treatments and almost complete removal of its residues and toxicological/mutagenic properties in surface water and water treatment plant; ii) removal of inorganic pollutants such as bromate, nitrate and nitrite iii) inactivation of mycobacteria and fungus; iv) conversion of CO2 in alcohols and v) hydrogen production, with the aim to improve the cost/benefit involved in water treatment. Although Ti/TiO2 nanotubes electrodes are semiconductors of ntype they can be self-doped by Ti3+ generated by using a simple cathodic polarization given a new electroanalytical approach in the development of electrochemical sensors with high sensitivity and selectivity for some amines and diuretics used in forensic analysis.