Highly efficient surface sequestration of Pb2+ and Cr3+ from water using a Mn3O4 anchored reduced graphene oxide: Selective removal of Pb2+ from real water. (July 2022)

• Record Type: Journal Article
• Authors: Lingamdinne, Lakshmi Prasanna; Godlaveeti, Sreenivasa Kumar; Angaru, Ganesh Kumar Reddy; Chang, Yoon-Young; Nagireddy, Ramamanohar Reddy; Somala, Adinarayana Reddy; Koduru, Janardhan Reddy
• Is Part Of: Chemosphere. Volume 299(2022)
• Publication Date: 2022-07
• Subjects: Mn3O4-Reduced graphene oxide nanocomposite -- Material properties -- Chemical processing -- Heavy metals -- Adsorption; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2022.134457
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Owing to the ubiquitous existence of detrimental heavy metals in the environment, simple adsorption-oriented approaches are becoming increasingly appealing for the effective removal of Pb 2+ and Cr 3+ from water bodies. These techniques use nanocomposites (NC) of reduced graphene oxide (rGO) and Mn3 O4 (rGO-Mn3 O4 ), they employ a hydrothermal technique featuring NaBH4 and NaOH solutions. Here, spectroscopic and microscopic instrumental techniques were used to evaluate the morphological and physicochemical characteristics of prepared reduced graphene oxide manganese oxide (rGO-Mn3 O4 ), revealing that it possessed a well-defined porous structure with a specific surface area of 126 m 2 g −1 . The prepared rGO-Mn3 O4 had significant adsorption efficiencies for Pb 2+ and Cr 3+, achieving maximum sequestration capacities of 130.28 and 138.51 mg g −1 for Pb 2+ and Cr 3+, respectively, according to the Langmuir model. These adsorption capacities are comparable to or greater than those of previously reported graphene-based materials. The Langmuir isotherm and pseudo-second-order models adequately represented the experimental results. Thermodynamic analysis revealed that adsorption occurred through spontaneous endothermic reactions. Recycling studies showed that the developed r-GO-Mn3 O4 had excellent recyclability, with <70% removal at the 5th cycle; its feasibility was evaluated using industrial wastewater, suggesting that Pb 2+ was selectively removed from Pb 2+ and Cr 3+ contaminated water. The instrumental analysis and surface phenomena studies presented here revealed that the adsorptive removal processes of both heavy metals involved π electron donor-acceptor interactions, ion exchange, and electrostatic interactions, along with surface complexation. Overall, the developed rGO-Mn3 O4 has the potential to be a high-value adsorbent for removing heavy metals. Graphical abstract: Image 1 Highlights: A simple hydrothermal reduction was used to synthesis rGO-Mn3 O4, then characterized. Effects of coexisting ions and selectivity on Pb 2+ and Cr 3+ removal were studied. Adsorption mechanisms of Pb 2+ and Cr 3+ on rGO-Mn3 O4 were elucidated. Feasible applicability of rGO-Mn3 O4 was revealed by treating waste water. Stability and re-usability of rGO-Mn3 O4 were extensively established.