Vol. 14 | No. 3 |2017-2023| July - September | 2021 ISSN: 0974-1496 | e-ISSN: 0976-0083 | CODEN: RJCABP http://www.rasayanjournal.com http://www.rasayanjournal.co.in Rasayan J. Chem., 14(3), 2017-2023(2021) http://doi.org/10.31788/RJC.2021.1436042 This work is licensed under a CC BY 4.0 license. THE PERFORMANCE OF GREEN SYNTHESIS OF GRAPHENE OXIDE PREPARED BY MODIFIED HUMMERS METHOD WITH OXIDATION TIME VARIATION U. Chasanah 1 , W. Trisunaryanti 1,  , Triyono 1 , H.S. Oktaviano 2 and D.A Fatmawati 1 1 Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Sekip Utara Bulaksumur, Sleman, D.I. Yogyakarta, 55281, Indonesia 2 Research & Technology Center, PT. Pertamina (Persero), Sopo Del Tower A, Floor 51, Jl. Mega Kuningan Barat III, Kawasan Mega Kuningan, Jakarta Selatan, DKI Jakarta, 12950, Indonesia  Corresponding Author: wegats@ugm.ac.id ABSTRACT Attempt to reduce oxidation time is an important step toward the green chemistry approach in GO synthesis process. Graphene oxide (GO) preparation by modifying the hummer method has been studied. GO was produced by mixing potassium permanganate (KMnO4), graphite powder, and sulfuric acid/phosphoric acid (H2SO4/H3PO4) with a variation oxidation time of 6h, 12h, and 18h. GO was characterized by UV–Visible spectroscopy, Fourier Transform InfraRed (FT-IR) spectroscopy, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy-Selected Area Electron Diffraction (TEM SAED). The results showed that even with 6h of oxidation time. GO has been successfully formed. GO-6h has characteristics almost the same as GO 12h and GO 18h that indicated reducing oxidation time was a success. Keywords: Graphene Oxide, Green Synthesis, Modified Hummer, Oxidation Time RASĀYAN J. Chem., Vol. 14, No.3, 2021 INTRODUCTION Graphene is a graphite monolayer that consists of carbon atom hybridization sp 2 of having hexagonal structures. 1 Graphite oxidation by using a strong oxidizing agent will change the structure of the graphite layer. 2 Graphite oxidation introduces several oxygen functional groups attached to its plane or its basal edges, which makes hydrophilic (GO) sheets form steady aqueous or neutral colloids. 3 Graphite has a similar layered structure as that of graphene oxide (GO), but the plane of carbon atoms in GO is heavily decorated by oxygen-containing groups, which not only expand the interlayer distance but also make the atomic-thick layers hydrophilic. As a result, these oxidized layers can be exfoliated under moderate ultrasonication. 4 GO is an oxidized chemical form of graphene. It consists of many molecular collections, for example, hydroxyl, carboxyl, and epoxy gatherings. 5 GO can be used as precursors to make reduced graphene oxide (rGO) but GO itself also has extraordinary physical and chemical properties that require materials sought for other applications that are provided electronically, biomedically, energy, and environmentally 6-8 , as adsorbing contaminants 9 , and solar desalination. 10 The Hummers method is often used in synthesizing GO because it is easier to do, efficient, inexpensive, and does not produce gas such as NO2, N2O4, or ClO2. 3 Synthesize GO from graphite using the modified Hummers method without using NaNO3 to avoid the release of altered gases such as NO2 and N2O4 4 and also residual ions (Na + and NO3 - ) during synthesis that will become wastewater. The modified Hummers method also produces carbon in addition to hydrophilic, better conductivity, no gas produced, and the result of GO is much better. 11 Modification of the Hummers method can be carried out using different amounts of graphite, different oxidant concentrations, reaction times, and temperatures used. 12