LAUSR

Abstract This paper presents a green biosynthetic approach of zinc oxide nanoparticles using co-precipitation method with dried fruit extract of Amomum longiligulare (A. longiligulare), as it is plant-derived reducing agent. For configuration of Al-ZnO NPs, the absorption of wavelength of nanoparticles was observed by UV–vis spectra at 354 nm. XRD (X-ray diffraction) micrograph and FE-TEM (Field-Emission Transmission Electron Microscopy) determined the morphological structure of green synthesized Al-ZnO. The chemical functional group, elemental mapping, and crystallization of nanoparticles were characterized by FTIR (Fourier Transform Infrared Spectroscopy), and EDX (Energy dispersive X-ray spectroscopy). The photocatalytic activity of Al-ZnO NPs was confirmed by photodegradation of methylene blue and malachite green dyes under 356 nm of UV light irradiation in aqueous solution. The degradation of MB with Al-ZnO NPs was completed with approximately 66 % in 60 min, whereas MG degradation was measured around 38.1 % by 60 min by Al-ZnO NPs respectively. The kinetic reaction rate as stated by first-order reaction of photocatalytic degradation of MB and MG with Al-ZnO NPs were found to be 0.014 min−1 and 0.008 min−1 respectively. Therefore, phytochemicals of A. longiligulare extract have capability to act as a reducing agent in biosynthesis of zinc nanoparticles and is suitable to produce cost-efficient and eco-friendly photocatalyst.