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A combined chemical-electrochemical oxidation method to obtain porous bioactive TiO 2 films on titanium is reported. In this case, a titanium chemical pre-etching followed by the micro-arc oxidation (MAO) treatment is proposed and optimized, to obtain a high-roughness and porous surface which benefits the titanium/bone integration. The MAO treatment at various rates (different current densities) allowed to define the influence of the oxide growth rate on the surface morphology and to design the best features for each case. Titanium samples were pre-etched using a 2% HF solution as a function of the etching time, and then anodized by the MAO treatment in a 0.5 M H 3 PO 4 solution at current densities in the 10 to 90 mA.cm -2 range. High porosity (0.5 to 1 µm-diameter pores) and higher phosphorous content for TiO 2 films were achieved by first etching the Ti sample for 180 seconds in the HF solution, and then applying current densities in the 80 to 90 mA.cm -2 range for the micro-arc oxidation process.

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In recent years, catalysis and photocatalysis processes using TiO2 nanoparticles (TNPs) have received great attention due to their effectiveness in degrading and mineralizing organic and inorganic compounds. Nanocrystalline TiO2 powder with different crystallinity and phase structures were synthesized using a Ti alloy as anode and stainless steel as cathode by the galvanostatic anodization method in alcoholic solution of chloride. Sodium dodecyl sulphate (SDS) surfactant was used as additive for to control the particle size. The X-ray diffraction (XRD), RAMAN spectroscopy and transmission electron microscopy (TEM) results, showed that a 50:50 anatase and brookite mixture phase was obtained with crystal sizes 7.2 nm and 7.5 nm respectively without any annealing. The size of the particles and the material purity are measured using scanning electron microscopy (SEM), dynamic light scattering (DLS) and energy dispersive X-ray analysis (EDX) indicated that a particle size smaller than 40 nm and a free impurity materials. The Brunauer–Emmett–Teller (BET) results show a specific surface area bigger than 200 m2/g. The band gap energy of the resulting TNPs were determined by diffuse reflectance measurements according to the Kubelka Munk theory, revealing a value of 3.24 eV. Therefore, the results indicate the success of this method to create TiO2 nanoparticles in aqueous medium with a good properties to be use like photocatalyst in a very economical and environmentally benign way.