Synthesis and Characterization of Graphene Oxide (GO) Obtained by Modified Hummer’s Method: Application to the Removal of Cadmium ions from Wastewater

Abstract

Abstract Through its outstanding mechanical, electrical, and chemical properties, graphene oxide has been regarded as a significant material since its discovery. This paper explains how to make graphene oxide (GO) using the Modified Hummer's method from pure graphite powder, which is the most prevalent approach. Multiple methods are been used to validate the physicochemical qualities and examine the morphological and structural aspects of the nano-composite sample, including Brunauer Emmett Teller, Fourier transform infrared spectroscopy, X-ray diffraction, and the scanning electron microscope (SEM). The objective of this study is to describe results from GO-based cadmium removal in aqueous solutions, followed by UV/VIS spectroscopy with xylenol orange indicator and a buffer solution pH=5, 8. Various parameters (contact time , pH, amount of support, initial concentration, temperature, ionic strength, pHpzc) were investigated in detail and the maximum adsorption capacity of the metal ion adsorbed by graphene oxide is 125 mg.g-1 .The Langmuir adsorption isotherm (R2≈0, 93) is found to suit the data better than the Freundlich and Temkin isotherms. Additionally, the kinetics of sorption are investigated using pseudo-first-order, pseudo-second-order, and Elovich models; the pseudo second order has been found to be the most suited to reflect the kinetic model (R2≈0, 99), and the thermodynamic parameters (ΔG°, ΔH° and ΔS°) are examined. The adsorption process is spontaneous and exothermic in character, as well as physical. Desorption characteristics and reusability of the produced material, on the other hand, are put to the test in five adsorption-desorption cycles.