Spectroscopic and morphological characterization of Nephelium lappaceum peel extract synthesized gold nanoflowers and its catalytic activity

Green methods using discarded fruit and vegetable waste are a safer alternative for the synthesis of metal nanoparticles, due to their simplicity, low cost and ecofriendly nature. In this investigation, the bioactive constituents of Nephelium Lappaceum L. (Rambutan) peel extract were effectively used as reducer to synthesize gold nanoflowers (AuNFs) and attempted to convert fruit waste into a valuable product. A quick and simple synthesis of bluish-purple color AuNFs was observed to occur with a plasmonic resonance band, lmax around 563 nm. Transmission electron microscopy and dynamic light scattering analysis confirming the formation of clusters of gold nanoparticle similar to flowers/AuNFs with a size of 70-115 nm and each monodispersed nanoparticles has an average size of 11.6 ± 2.35 nm. Fourier transform infrared spectroscopy confirmed that the AuNFs were capped with hydroxyl (-OH) and carboxyl (-COOH) groups of rambutan peel. In addition, the resulting AuNFs showed catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol (1.9089 × 10-1 min−1, R2 = 0.969), efficiently. The suggested synthetic method is facile, sustainable, cost-effective and convenient for the development of value-added products in future nanotechnology products.