Characterization and Photoluminescent, Photocatalytic and Antimicrobial Properties of Boron-Doped TiO2 Nanoparticles Obtained by Microwave-Assisted Solvothermic Method

Boron doped TiO2:xB (x = 0 mol.%, 1 mol.%, 2 mol.%, 4 mol.% and 8 mol.%) was quickly synthesized by a microwave-assisted solvothermic method at 140 degrees C for 10 min. The nanoparticles obtained were characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy, Raman spectroscopy, photoluminescence, field emission scanning electron microscopy, electron microscopy and diffuse optical reflectance. The photocatalytic properties were estimated against methylene blue dye. The antimicrobial activity was measured by the disc diffusion technique against S. aureus and E. coli bacteria. The XRD patterns show that there was no formation of secondary phases and that all the peaks correspond to the anatase phase of TiO2. Rietveld's refinement showed that the addition of B3+ in the TiO2 lattice promotes a reduction in the size of the crystallites and this reduction it effectively increases the degradation capacity of the methylene blue dye, which after 50 min the 8%B sample degraded completely, while the pure TiO2 sample reduced its concentration by 95%. Boron-doped TiO2 was effective when reused and after the third cycle the photocatalytic activity of the powders was maintained. In addition, the incorporation of 8%B in the TiO2 lattice resulted in an increase from 8.66 mm to 15.61 mm and 9.04 mm to 13.65 mm in the inhibition halos of the S. aureus and E. coli bacteria, respectively.