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The effect of the addition of zirconia in the photocatalytic behaviour of titania is analysed. In order to increase the ways for reagent and product diffusion in the material, a sol-gel hydrothermal synthesis route using Tween-20 as a directing agent to obtain a hierarchical macro-mesoporous structure is proposed. Nanostructured macro-mesoporous TiO2/ZrO2photocatalyst with 0, 10, 20, 30, and 100% mol of ZrO2were obtained and calcined at different temperatures. The crystalline structure was analyzed by X-ray diffraction and TEM. The porosity was confirmed by SEM, TEM, and nitrogen adsorption-desorption isotherms. The worm-like mesoporous structure was confirmed by TEM. The specific surface areas obtained by Brunauer-Emmet-Teller method (BET) ranged from 125 to 180 m2/g. The Tween-20 total elimination from the structure by thermal treatment was confirmed by infrared spectroscopy and thermogravimetric analysis. Additionally, the photocatalytic effect of the zirconia addition was studied in the methylene blue (MB) degradation reaction, and the best photocatalytic activity was obtained in the sample with 10% mol of ZrO2, degrading up to 92% the MB.

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The increased use of the Ti6Al4V alloy as prosthetic material has been questioned by different authors who have confirmed its ion release when undergoing a corrosion attack by body fluids. In this work the coating of the Ti6Al4V alloy with nanostructured Zirconia is proposed through the colloidal electrophoretic deposition method (CEDP). The coatings were thermally treated at 450°C, 500°C, 600°C, 650°C and 700°C. The effect of the thermal treatment temperature on the morphology and phase content was evaluated by field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). Corrosion resistance of the Ti6Al4V alloy and the ZrO2/Ti6Al4V system was evaluated by Tafel extrapolation, polarization resistance and electrochemical impedance spectroscopy in artificial saliva media with a pH of 7.4 at a temperature of 37°C, using an aereated electrochemical cell to simulate human buccal conditions. The Ti6Al4V alloy showed good corrosion resistance by forming a passivation TiO2 layer on the metal surface, but there was an increase in the resistance when the Ti6Al4V alloy was coated with ZrO2. It showed lower values in the icorr, corrosion rate and ion release, a higher impedance modulus and a substantial polarization resistance after 24 hours.