Simple synthesis of multifunctional bismuth selenide nanoparticles; structural, optical characterizations and their effective antibacterial activity

This paper reports on the antibacterial properties of bismuth selenide prepared by cost effective methods; sol–gel and hydrothermal method for which 2:3 of bismuth nitrate pentahydrate and elemental selenide are used. X-ray diffraction (XRD), ultraviolet–visible absorption (UV–Vis.) and Fourier-transform infrared spectroscopy (FTIR) were carried out to characterize the synthesized samples. Structural analysis of synthesized samples using XRD revealed that the grain size of samples is nanosized and possess crystalline nature showing orthorhombic structure (sol–gel) with average grain size of particles to be 24.05 nm (standard deviation 4.55 nm), and rhombohedral (hydrothermal) with average grain size of particles to be 12.20 nm (standard deviation 3.3 nm). UV–Vis analysis revealed the absorption region for Bi 2 Se 3 nanoparticles and their corresponding energy bandgap between 1.47eV and 1.74 eV range. FTIR spectrum shows the region of vibrational stretching between 600cm -1 and 1000 cm −1 that corresponds to Bi and Se bonding. Disk diffusion method was used to check the antibacterial activity successfully against gram-positive bacteria S. aureus and gram-negative bacteria E. coli.