Carbon-based nanohybrid fabricated in-situ and boosted the adsorption of anionic reactive yellow dye

Abstract

The purpose of this research is to report a unique manipulation of producing carbon nanotubes/carbon xerogel (CNTs/CX) hybrid loaded with bimetallic catalysts of Fe–Ni via one-step chemical vapor deposition (CVD) of camphor. Active bimetallic catalysts were formed during carbonization of resorcinol–formaldehyde xerogel at 800 °C to form carbon xerogel (CX); meanwhile, the carbon gas was librated from camphor at 220 °C for 45 min. CX and CNTs/CX samples were analyzed using measurements of transmission electron microscope (TEM), X-ray diffraction tool (XRD) and Fourier transform infrared spectroscopy (FTIR). Further, the liquid-phase adsorption of a reactive yellow 160 (RY160) dye on CX and CNTs/CX samples and thermodynamic studies were investigated. TEM and XRD results revealed the formation of carbon nodules in CX combined with bundles of CNTs having outer diameters ranged from 40 to 80 nm in CNTs/CX. Adsorption of RY160 dye was highly relied on pH, temperature, initial dye concentration and contact time. Through kinetic modeling, pseudo-second-order kinetic model expressed closely the experimental data of RY160 adsorption. Equilibrium adsorption studies declared that the Freundlich model is the better with adsorption of RY160 on CNTs/CX due to it has heterogeneous surface character resulting from combination of CX and CNTs. Langmuir adsorption capacity (q _L, mg/g) values exhibited that CNTs/CX sample have a superior adsorption of RY160 dye which were reached to 167 mg/g than that by CX (q _L = 125 mg/g). Thereof, the produced CX and CNTs/CX samples present higher removal capacity and can be employed successfully for RY160 dye removal from a textile wastewater.