Estimating the degradation of methylethionium chloride dye on nanotubular TiO₂ structure

In this study the photocatalytic behavior of as-anodized and heat treated surfaces of Ti6Al4V was investigated electrochemically in methylethionium chloride solution in dark and under illumination at 60W and 100W. X-ray diffraction pattern of as-anodized surface revealed oxygen deficient Ti₆O phase, which was converted to rutile/anatase phases by heat treatment in air. Potentiodynamic scans showed variation in current density during anodic polarization due to the electronic traps within sub-band energy states by the amorphous nature of as formed structure hence lower catalytic activity than heat-treated specimen. Impedance spectroscopy of heat-treated surface in dye solution under dark and light depicted lower charge transfer resistance, recombination admittance and higher charge transfer coefficient than as-anodized. The UV-vis spectroscopy of heat treated TiO₂ nanotubular structure represented 45.05% photocatalytic efficiency.