Bifunctionalization of nano-polyaniline and manganese dioxide with graphene oxide for fast and efficient removal of Cu(II) ions from industrial effluents

Recent advancements in industry, technology, the economy, and society have exacerbated environmental pollution issues, especially concerning water systems. Copper represents a considerable danger to aquatic environments because of its non-biodegradable characteristics and related health risks. This study presents an environmentally sustainable and practical method for synthesizing a bi-functionalized graphene oxide-based nanocomposite (MnO₂/PANI@GO), which integrates manganese dioxide and nano-polyaniline, designed for the efficient extraction of Cu(II) from aqueous solutions. At pH 7.0 and 25 °C, the application of 40.0 mg of the synthesized nanocomposite resulted in a remarkable Cu(II) removal efficiency of 99.6%, with an adsorption capacity of 216.4 mg.g -1 , for an initial Cu(II) concentration of 10 mg.L -1 . The nanocomposite's structural and morphological properties were studied using various analytical techniques, including FTIR, XRD, Raman spectroscopy, SEM, and HRTEM imaging. Additionally, kinetic analysis was conducted to clarify the adsorption characteristics of Cu(II) onto the nanocomposite. The adsorption process was optimally characterized by a pseudo-second-order kinetic model, indicating that chemisorption is the prevailing mechanism. The Langmuir isotherm model indicated monolayer adsorption of Cu(II) on the adsorbent surface. This study illustrates the promise of a sustainably synthesized MnO₂/PANI@GO nanocomposite, produced from inexpensive or waste-derived resources, as an effective and economical option for the remediation of heavy metal-contaminated water.