Efficacy of titanium doped-indium tin oxide (Ti/TiO2–ITO) films in rapid oxygen generation under photocatalysis and their suitability for bio-medical application

Abstract

The present work describes in detail the photocatalytic properties of controlled titanium doped indium tin oxide (Ti/TiO₂–ITO) composite thin films prepared by DC magnetron sputtering and their applicability to developing a bio-medical lung assistive device. The catalytic films of various thicknesses (namely, C₁, C₂, C₃ and C₄) were characterized using surface imaging (SEM), X-ray analyses (XRD and EDX), and Raman studies. The optical band gaps of the prepared films are ∼3.72–3.77 eV. Photocatalytic efficiencies of the film catalysts were investigated with the aid of a model organic molecule (Rhodamine B dye). The overall photodegradation capacity of the films was found to be slow kinetically, and the catalyst C₁ was identified as having a better degradation efficiency (RhB 5 ppm, at pH 6.5) over 5 h under irradiation at 254 nm. The distinctive features of these composite films lie in their oxygen accumulation capacity and unique electron–hole pair separation ability. Investigations on oxygen species revealed the formation of superoxide radicals in aqueous systems (pH 6.5). The prepared films have TiO₂ in the anatase phase in the surfaces, and possess the desired photocatalytic efficiency, compatibility to the heme system (are not involved in harmful hydroxyl radical production), and appreciable reusability. Especially, the thin films have a significant ability for mobilization of oxygen rapidly and continuously in aqueous medium under the irradiation conditions. Hence, these films may be a suitable choice for the photo-aided lung assistive design under development.