Contents lists available at ScienceDirect Journal of Hazardous Materials journal homepage: www.elsevier.com/locate/jhazmat Highly potent radical scavenging-anti-oxidant activity of biologically reduced graphene oxide using Nettle extract as a green bio-genic amines- based reductants source instead of hazardous hydrazine hydrate Mahsa Mahmudzadeh, Hossein Yari ⁎ , Bahram Ramezanzadeh ⁎ , Mohammad Mahdavian Department of Surface Coatings and Corrosion, Institute for Color Science and Technology (ICST), Tehran, Iran GRAPHICALABSTRACT ARTICLEINFO Keywords: Hazardous hydrazine hydrate Green reductant Graphene oxide Nettle extract Bio-genic amines XPS ABSTRACT Reduced graphene oxide (rGO) is relied upon to be the most promising candidate for high-profciency. Hydrazine is the most conventional efcient reducing agent that has been frequently used for reduction of graphene oxide, however, it is not environmentally safe due to its toxic nature, causing unsatisfactory defects on the basal plan of GO. Therefore, employing green and efcient reducing agents from natural sources like plant extracts has be- come the research interest for obtaining high quality reduced graphene oxide sheets in recent years. Here a one-step, easy, cost-efective and green synthesis method based on Nettle leaves’ extract has been introduced as an efective reduction method of graphene oxide compared with the toxic and harmful Hydrazine hydrate substance. In this study, GO and rGO were obtained from various methods and characterized by Raman spectroscopy, feld emission scanning electron microscope, high-resolution transmission electron microscope (HR-TEM), X-ray difraction analysis (XRD) and X-ray photon spectroscopy (XPS) analysis. Results of diferent analytical techniques revealed that the Nettle leaves’ extract could successfully reduce GO sheets to high per- formance reduced graphene oxide with 79% efciency in comparison with conventional Hydrazine hydrate. On the other side the rGO obtained by Nettle solution could scavenge the free radicals with 70% inhibition capacity at least concentration. Existence of Histamine and Serotonin and many other polyphenols as a part of Nettle leaves composition by following anti-oxidants mechanisms (H donation or electron transfer) promote the anti- https://doi.org/10.1016/j.jhazmat.2019.03.046 Received 18 December 2018; Received in revised form 6 March 2019; Accepted 11 March 2019 ⁎ Corresponding authors. E-mail addresses: yari-ho@icrc.ac.ir (H. Yari), ramezanzadeh-bh@icrc.ac.ir, ramezanzadeh@aut.ac.ir (B. Ramezanzadeh). Journal of Hazardous Materials 371 (2019) 609–624 Available online 12 March 2019 0304-3894/ © 2019 Elsevier B.V. All rights reserved. T