The carrier transport properties and photodegradation ability of low temperature synthesized phase pure rutile titanium oxide nanostructured materials

Abstract

Abstract In this study, we report synthesis of pure rutile phase titanium oxide (TiO2) nanoparticles (NPs) at a considerably low temperature with particle size ca. 20 nm (from TEM). The sample showed mesoporous nature as per Brunauer- Emmett- Teller (BET) method with a surface area of 211.7 m2 g−1and band gap 2.94 eV stretching into the visible portion of the electromagnetic spectrum. Two Indium tin oxide (ITO)/TiO2 (rutile and commercial)/Aluminium (Al) based heterojunctions were fabricated and carrier transport properties evaluated with the help of space charge limited current (SCLC) theory. The values of mobility and transit time for rutile were 7.44 × 10−7 m2V−1s−1and 9.52 × 10−5 s respectively and were found to be enhanced on illumination in comparison to commercial TiO2. Rutile exhibited a higher photosensitivity of 5.48 which predict photo-switching nano device applicability. Impedance analysis showed stable and enhanced photocurrent response. The degradation ability of rutile for malachite green oxalate (MG), a hazardous dye, was also checked and found to be 97.54% in 3 h being comparable to commercial TiO2 when irradiated with a definite dose of ultraviolet (Uv) radiation (1.035 × 10−15 Jsm2). The Langmuir- Hinshelwood model was delineated to calculate the reaction rate which was higher for rutile (0.0183 min−1). Lower electron hole pair (EHP) recombination was proved for rutile by photoluminescence (PL) measurements.