Synthesis of a carbon@Rectorite nanocomposite adsorbent by a hydrothermal carbonization process and their application in the removal of methylene blue and neutral red from aqueous solutions

Carbon@REC nanocomposite (C@REC) was synthesized by a hydrothermal carbonization process, and characterized by XRD, Fourier transform infrared spectroscopy, thermal gravimetric analysis, SEM, nitrogen adsorption–desorption measurements, and zeta potential analysis. The adsorption property of the C@REC was investigated as a function of pH of solution, adsorbent dosage, contact time, and initial concentration of MB and NR. The results suggest that amorphous carbon supported on the surface of rectorite. The adsorption experiment showed that adsorption kinetics of MB and NR onto the followed the pseudo-second-order kinetic model. The adsorption isotherm data were fitted well to the Langmuir isotherm. The adsorption capacities for the removal of MB and NR on the C@REC determined using the Langmuir equation were 15.68 and 20.30 mg g−1, respectively.