Green synthesis of gold nanoparticles supported in Al-pillared bentonite using aqueous leaf extracts of Dracaena angustifolia and their use for reductive degradation of methyl orange

Abstract

We obtained the green synthesis of gold nanoparticles (AuNPs) using suji leaf extract (Dracaena angustifolia) and used the AuNPs to reduce methyl orange. The active substance in suji leaf extract was determined using phytochemical tests to identify components such as terpenoid, steroid, alkaloid, polyphenol, flavonoid, and saponin. The catalyst Al–bentonite@AuNP was prepared by immobilizing HAuCl4 in Al–pillared bentonite, which was then reduced using various concentrations of suji leaf extract [0.1 %–1 % (w/v)]. The AuNPs were characterized using UV–vis spectroscopy and transmission electron microscopy, and the Al–bentonite@AuNP catalyst was characterized using Fourier transform infrared spectroscopy and X-ray diffraction. The application of Al–bentonite@AuNP as catalyst in the reductive degradation of methyl orange yields a degradation percent of up to 34.5 %.