• Choudhary, Nisha
• Chundawat, Rajendra Singh
• Amari, Abdelfattah
• Meena, Abhishek
• Mahdhi, Noureddine
• Patel, Ashish
• Yadav, Virendra Kumar
• Sahoo, Dipak Kumar
• Rathore, Chandani
• Egbosiuba, Titus Chinedu

Abstract

<jats:p>Over the last decade there has been a huge increase in the green synthesis of nanoparticles. Moreover, there is a continuous increase in harnessing the potential of microorganisms for the development of efficient and biocompatible nanoparticles around the globe. In the present research work, investigators have synthesized TiO<jats:sub>2</jats:sub> NPs by harnessing the potential of <jats:italic>Bacillus subtilis</jats:italic> MTCC 8322 (Gram-positive) bacteria. The formation and confirmation of the TiO<jats:sub>2</jats:sub> NPs synthesized by bacteria were carried out by using UV-Vis spectroscopy, Fourier transforms infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDX/EDS). The size of the synthesized TiO<jats:sub>2</jats:sub> NPs was 80–120 nm which was spherical to irregular in shape as revealed by SEM. FTIR showed the characteristic bands of Ti-O in the range of 400–550 cm<jats:sup>−1</jats:sup> and 924 cm<jats:sup>−1</jats:sup> while the band at 2930 cm<jats:sup>−1</jats:sup> confirmed the association of bacterial biomolecules with the synthesized TiO<jats:sub>2</jats:sub> NPs. XRD showed two major peaks; 27.5° (rutile phase) and 45.6° (anatase phase) for the synthesized TiO<jats:sub>2</jats:sub> NPs. Finally, the potential of the synthesized TiO<jats:sub>2</jats:sub> NPs was assessed as an antibacterial agent and photocatalyst. The remediation of Methylene blue (MB) and Orange G (OG) dyes was carried out under UV- light and visible light for a contact time of 150–240 min respectively. The removal efficiency for 100 ppm MB dye was 25.75% and for OG dye was 72.24% under UV light, while in visible light, the maximum removal percentage for MB and OG dye was 98.85% and 80.43% respectively at 90 min. Moreover, a kinetic study and adsorption isotherm study were carried out for the removal of both dyes, where the pseudo-first-order for MB dye is 263.269 and 475554.176 mg/g for OG dye. The pseudo-second-order kinetics for MB and OG dye were 188.679 and 1666.667 mg/g respectively. In addition to this, the antibacterial activity of TiO<jats:sub>2</jats:sub> NPs was assessed against <jats:italic>Bacillus subtilis</jats:italic> MTCC 8322 (Gram-positive) and <jats:italic>Escherichia coli</jats:italic> MTCC 8933 (Gram-negative) where the maximum zone of inhibition in <jats:italic>Bacillus subtilis</jats:italic> MTCC 8322 was about 12 mm, and for <jats:italic>E. coli</jats:italic> 16 mm.</jats:p>

Topics

• nanoparticle
• impedance spectroscopy
• phase
• scanning electron microscopy
• x-ray diffraction
• titanium
• Energy-dispersive X-ray spectroscopy
• Ultraviolet–visible spectroscopy