Capabilities of Novel Carbon Nano Adsorbents in Evaluating the Extraction of 2-Nitrophenol and Heavy Metal from Aqueous Solutions

Abstract

This study primarily focused on evaluating the efficacy of Metal Oxide-infused Carbon Nano Adsorbents (CNAs), which included both Carbon Nanotubes and Carbon Nanofibers, in removing Cd⁺², Cr⁺³, and 2-NP from water solutions. We synthesized and analyzed four distinct types of CNAs, each impregnated with either Al₂O₃, TiO₂, Fe₂O₃, or Cu₂O₃. The metal content in these CNAs was determined by comparing their dry and calcined weights. To investigate their properties, we utilized various techniques such as Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, Energy-Dispersive X-ray Spectroscopy (EDX), and Thermal Gravimetric Analysis (TGA). These methods helped us understand their morphological traits, surface areas, pore structures, metal oxide distributions, and thermal stabilities, thereby confirming their adsorption effectiveness for pollutants. The findings indicated that CNAs altered with metal oxides showed higher surface areas and adsorption abilities than their unmodified counterparts. Specifically, CNAs/TiO₂ exhibited the most significant increase in surface area (140 m²/g) and pore volume (0.460 cm³/g), which resulted in an enhanced adsorption capacity for Cd⁺³ at 11.4 (mg/g), surpassing the 9.5 (mg/g) capacity of pure CNAs with surface area (90 m²/g) and Pore volume (0.331 cm³/g). Similarly, CNAs/Al₂O₃ demonstrated an increased surface area of 100 (m²/g), surpassing that of pure CNAs. This enhancement led to a significant improvement in adsorption capacities, elevating the uptake for Cr⁺³ from 32.2 to 52 (mg/g) and for 2-NP from 24.8 to 49.6 (mg/g). This enhancement in adsorption efficiency is attributed to the increased surface area and improved surface chemistry due to the incorporation of Titania and Alumina, which proved more effective than modifications with copper oxide and Ferric oxide. These insights emphasize the significance of selecting appropriate metal oxides for modifying CNAs, as this can greatly impact their ability to target various contaminants, thus contributing to the development of more advanced water purification methods using CNAs/MO.