Exploitation of de-oiled jatropha waste for gold nanoparticles synthesis: A green approach

A novel single step green-synthesis route has been developed for the synthesis of gold nanoparticles using aqueous extract of de-oiled jatropha waste (DJW). DJW, a second stage waste, was adopted as a reducing agent to reduce HAuCl4. Different optimal parameters such as ratio of HAuCl4(aq)/DJW(aq), reaction temperature and pH effects were also studied to fine-tune the shape of the gold nanoparticles (AuNPs). The resultant AuNPs were characterized by UV-visible spectrometry, Transmission electron microscopy, Selected area electron diffraction, Powder X-ray diffraction and Fourier transform infrared spectroscopy. Triangle, hexagonal and spherical shaped AuNPs were obtained with the average particle size of ∼14 nm. Furthermore, the AuNPs were capped and efficiently stabilized by protein molecules present in the DJW. In short, this novel synthesis route provides an environmental friendly and low cost option, as compared to currently available expensive chemical and/or physical methods.