Synthesis of Co-Doped TiO2 Nanoparticles using leaf extract of Millettia ferruginea for photocatalytic and antibacterial applications

Abstract

Photocatalysis is an efficient technique for reducing environmental contamination caused by organic pollutants. The present study investigated the photocatalytic and antibacterial activity of nanomaterial composed of Titanium Oxide (TiO2), and cobalt doped Titanium oxide (Co-doped TiO2). TiO2 and Co-doped TiO2 nanomaterials were synthesized in greener way using cheap and easily available Ethiopian endemic plant extract known as Millettia ferruginea. This green and plant templated method of nanomaterial synthesis avoids using hazardous chemicals and use ecofriendly plants extract. The synthesized materials were characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), UV–Vis diffuse reflectance spectroscopy (UV-Vis DRS), Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM). The synthesized undoped TiO2, 2% Co-doped TiO2, 4% Co-doped TiO2, and 6% Co-doped TiO2 were investigated for their photocatalytic activity against methylene blue (MB) dye. Among them, the 6% Co-doped TiO2 Nanoparticle was found to be better photocatalysts with adigradation efficiency of 93.4% under visible light irradiation. Further, parameters such as effect of pH of the dye solution, catalyst loading and initial dye concentration were also studied and optimum degradation efficiencies were found at pH 9, catalyst load of 20 mg, and with dye concentration of 10 ppm. The synthesized TiO2 and Co-doped TiO2 nanomaterials were also applied against Gram-negative (E. coli and P. aeruginosa) and Gram-positive (S. aureus and S. pyogenes) bacterial strains to evaluate their antibacterial activities. The 6% Co-doped TiO2 Nanoparticles was shown to have better inhibition zone against all tested bacterial strains except S. aureus when compared to other synthesized nanomaterials for antibacterial activity.