A mechanistic approach toward unveiling a mechanism of formation of single crystalline gold (Au) nanoplates via a novel green synthetic route, using an aqueous extract of red beetroot waste (BRW) i.e peel, at room temperature(Deokar and Ingale, 2018). However, use of chemical methods for the synthesis of nanoparticles exhibited many drawbacks including harmful nature of solvents, reagents and the reducing environment that might result in the contamination in end product or may generate some risky by-product. Application of the green chemistry principles for nanostructure synthesis is a challenging task. No doubt there are varieties of reports of green synthesis of the nanoparticles using a plant material(Shankar et al., 2004), but using waste material from the plant is the novelty of this work. Previous reports on waste mediated nanoparticle synthesis includes our major contribution like banana peel(Deokar and Ingale, 2016) and the crystallinity dependent study focusing the potential of the beetroot peel aqueous extract(Deokar and Ingale, 2017)
Here in we report a novel green method for mechanical study of the single crystalline triangular nanoplates. The green method examined using UV-VIS spectroscopy, the existence of metallic gold validated using EDS and XPS, structure and orientation of the gold nanostructures examined using XRD. The active biomolecules present in the BRW aqueous extract that are responsible for reduction, confirmed using XPS and FTIR spectroscopy. These significant characterisations, unveiled a probable three-step mechanism for nanoplate synthesis. First, formation of the nanosphere, second its transformation into icosahedrons and finally 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 {111} lattice plane as their basal planes.
References
Deokar, G.K., Ingale, A., 2017. Green synthesis and study of crystallinity of AuNps. Acta Crystallogr. Sect. A Found. Adv. 73, C496–C496. doi:10.1107/S2053273317090775
Deokar, G.K., Ingale, A.G., 2018. Unveiling an unexpected potential of beetroot waste in green synthesis of single crystalline gold nanoplates: A mechanistic study. Arab. J. Chem. doi:10.1016/j.arabjc.2018.03.016
Deokar, G.K., Ingale, A.G., 2016. Green synthesis of gold nanoparticles (Elixir of Life) from banana fruit waste extract – An efficient multifunctional agent. RSC Adv. 6, 74620–74629. doi:10.1039/C6RA14567A
Shankar, S.S., Rai, A., Ankamwar, B., Singh, A., Ahmad, A., Sastry, M., 2004. Biological synthesis of triangular gold nanoprisms. Nat. Mater. 3, 482–8. doi:10.1016/j.jcis.2004.03.003
