Photocatalytic, antioxidant, and antibacterial activities of biocompatible MgO flake-like nanostructures created using Piper betle leaf extract

Abstract

In this study, biocompatible magnesium oxide (MgO) nanostructures were synthesized using an aqueous solution of Piper betle leaf methanolic extract. The color change during the synthesis process, i.e., colorless to dark brown solution, indicates the formation of MgO nano structures which is further confirmed through UV–Visible spectrum that exhibited characteristic absorption band at 329 nm. Results obtained from morphological analysis reveal that MgO nano flakes (MgO NFs) are present as triangular and polyhedral shapes having an average size ranging between 150 and 200 nm with clear lattice fringes. Secondary metabolites were clearly identified from the FTIR spectrum, and they helped in reduction and stabilization during the synthesis of MgO NFs. The XRD pattern displayed Braggs planes of (111), (220), (220), (311), and (222) with a face centered cubic (FCC) structure, which was further confirmed from the SAED pattern using HRTEM analysis. The as-synthesized MgO NFs manifested profound antimicrobial activity against gram positive as well as gram-negative bacteria with favorable biocompatibility. Furthermore, methylene orange dye was degraded almost completely (98.36 %) in the presence of MgO NFs photo catalysts within 1 h of sunlight illumination. In addition, MgO NFs displayed high level of antioxidant properties with recorded IC50 value of 15.89 μg/ml.