Micro arc oxidation of S-containing TiO{sub}2 films by sulfur bearing electrolytes

摘要

Porous S-containing titania (TiO{sub}2) films were fabricated by micro arc oxidation (MAO) in sulfur bearing electrolytes. Two kinds of electrolytes, Na{sub}2SO{sub}3 solution and Na{sub}2S{sub}2O{sub}3 solution, were used in the experiment. The influence of electrolyte and applied voltage on the structure and surface morphology of prepared TiO{sub}2 films has been evaluated. The critical voltage for film generation is 150 V in Na{sub}2SO{sub}3 solution and 100 V in Na{sub}2S{sub}2O{sub}3 solution. Under applied voltage of 250 V, the thickness of the TiO{sub}2 film is 15μm for Na{sub}2SO{sub}3 electrolyte and 25μm for Na{sub}2S{sub}2O{sub}3 electrolyte, respectively. The films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) later. Two main phases, anatase and rutile, are contained in the porous film. Detailed reaction mechanism of MAO process was discussed later, and it is concluded that TiO{sub}2 films are more easily prepared in Na{sub}2S{sub}2O{sub}3 solution due to sulfur deposition.