Aminated multi-walled carbon nanotubes doped magnetic flower-like FeSe2 nanosheets towards efficient adsorption in acidic wastewater

•Successful doping of CNT-NH2 in magnetic flower-like nanocomposites.•The protonation of amino groups under acidic conditions is utilized to give the composite a higher adsorption capacity under acidic conditions.•The composites exhibited good adsorption properties for Cu2+ and organic dyes. To improve the quality of water bodies, it is essential to remove pollutants effectively. Adsorption has proven to be an efficient method for this purpose. However, many commonly used adsorbents have drawbacks like instability in their structure and poor solid-liquid separation and adsorption recovery capabilities. In this study, we present a new adsorbent, FeSe2@Fe3O4@CNT-NH2, which is a composite material consisting of aminated multiwalled carbon nanotubes (CNT-NH2) doped with flower-like nanocomposite FeSe2@Fe3O4. The unique design of this adsorbent allows for protonation of the anionic or neutral groups present in the material under acidic conditions. As a result, it exhibits a significantly higher adsorption capacity for dyes through ion exchange, particularly methylene blue (MB) and rhodamine B (RB). The presence of FeSe2 and CNT-NH2 in the composite provides additional adsorption sites, thereby enhancing its overall adsorption efficiency. The experiments showed that the synthesized composites achieved maximum adsorptions of 15.82 mg/g for MB and 33.54 mg/g for RB, respectively. This novel adsorbent demonstrates improved performance in treating acidic wastewater while minimizing the risk of secondary contamination. This research opens up new possibilities for effective water treatment and highlights the importance of developing sustainable solutions for a healthier environment. [Display omitted] Scheme 1.