Unveiling an unexpected potential of beetroot waste in green synthesis of single crystalline gold nanoplates: A mechanistic study

Abstract

A novel green synthetic route developed toward unveiling a mechanism of formation of single crystalline gold (Au) nanoplates, with a flat surface using an aqueous extract of red beetroot waste (BRW) i.e. peel, at room temperature, the first time. The green method monitored using UV–VIS spectrophotometry, the presence of metallic gold, its structure; orientation and the responsible biomolecules; for reduction validated using EDS, XPS, XRD and FTIR spectroscopies respectively. Based on these significant characterizations, a probable three-step mechanism proposed here for nanoplate synthesis. First, the synthesis of the nanosphere, second its transformation into icosahedrons and ultimately its fragmentation into triangular nanoplates. The green synthetic mechanism for these nanoplates is investigated, validated and evidenced by both HR-TEM and XRD studies. The selected area electron diffraction (SAED) patterns and the assessment of Moire’ fringes confirmed that the nanoplates formed in this manner found single crystalline efficiently oriented in {1 1 1} lattice plane as their basal planes. Keywords: Green synthesis, Gold nanoplates, Mechanistic study, Single crystalline, Beetroot, Waste, PRODUCTIVELY, Triangular, X-ray photon spectroscopy (XPS), HR-TEM