Lemon Juice Assisted Green Synthesis of Reduced Graphene Oxide and Its Application for Adsorption of Methylene Blue

Abstract

Sustainable synthesis of reduced graphene oxide (rGO) is of crucial significance within the development of carbon nanomaterials. In this study, a green and eco-friendly strategy for the synthesis of rGO using lemon juice as the reducing agent for graphene oxide (GO) without using toxic and harmful chemicals was demonstrated. The reduction with lemon juice effectively eliminated the oxygen-containing functionalities of GO and regenerated the conjugated systems as confirmed by the UV-vis and FTIR spectroscopic and X-ray diffraction analyses. Microscopic evaluation showed the successful manufacturing of exfoliated and separated few layers of nano-sheets of rGO. The application of the resultant rGO as an adsorbent for organic pollutants was investigated using methylene blue (MB) as a model. The adsorption kinetics of MB on rGO is best matched with the pseudo-second-ordered kinetic model and the Langmuir model with a high adsorption capacity of 132.2 mg/g. The rGO exhibited good reusability with a removal efficiency of 80.4% in the fourth cycle. This green method provides a new prospect for the large-scale production of rGO in a cost-effective and safe manner.

Effects of Barium‐Copper‐Cobalt oxide composites supported on reduced graphene oxide in the thermolysis of ammonium perchlorate and 3‐nitro‐1,2,4‐triazol‐5‐one

“…The optical band‐gap energy of GO, and rGO was estimated to be 4.2, and 2.0 eV, respectively. The band‐gap energy agreed with the previously reported value [35] …”

“…The band-gap energy agreed with the previously reported value. [35] Thermal studies TG curves of NTO, NTO + BCC, and NTO + BCC/rGO are depicted in Figure 5, and corresponding DTA curves are given in Figure 6. NTO decomposes in a single step with a maximum mass loss (T m ) at ∼ 259-261 °C.…”

Green Coffee Bean Extract Assisted Facile Synthesis of Reduced Graphene Oxide and Its Dye Removal Activity

“…Similar result was also noticed for previously reported rGO. [20,30,51] The effective formation of exfoliated and segregated layer structures of rGO sheets by the reduction of GO using GCBE is also demonstrated by the TEM image in Figure 6. Typically, the exact number of layers of rGO sheets in the 2D image is not worth considering from TEM analysis, but unobservable graphitic aggregates strongly suggest the substantial formation of exfoliated rGO sheets in a similar way to previously described rGO.…”

“…[29] Mahiuddin et al used lemon juice for the reduction of GO and get rGO, which was employed as an adsorbent to remove MB. [30] Suresh et al used Cinnamon (Cinnamomum zeylanicum) extract for the reduction of GO and get rGO, which was used as an adsorbent to remove organic dyes and as an antioxidant. [31] Although much effort has been done, standardizing rGO synthesis is still a difficult endeavor, especially given the influence of the synthesis parameters.…”

Removal of methylene blue and safranin orange pollutants from liquid effluents by soy residue

“…However, when the pH of the MB solution is greater than pKa, consequently MB becomes unprotected; however, it still exists in the form of a positive charge, becoming mono-cationic, and then the electrostatic attraction between the carboxylate anion and the MB cation in the adsorbent increases. [69] In the same sense, the dye SO is in a protonated form up to pH 11 due to the binding of hydrogen ions to the amino group ( NH 2 ), as well as the reduction to the deprotonated form at pH above its pKa. [70] Likewise, at the natural pH of okara (6.8), MB and SO adsorbates are in a protonated form, showing high adsorption affinity on negatively charged surfaces.…”