Mechanical grinding mediated lanthanum modified silicon carbide based nitride carbon composite material enhances adsorption of dye wastewater

Abstract

In this work, a novel La_x-g-C₃N₄@β-SiC composite adsorbent was synthesized by thermal polycondensation and mechanical methods. The samples were analyzed by characterization methods such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The La₁₂-g-C₃N₄@β-SiC sample presented a more porous layered morphology with a uniform pore structure. In addition, the application of these materials in the adsorption and removal of new organic pollutants was studied. The results show that La₁₂-g-C₃N₄@β-SiC has a good adsorption effect on both alizarin red S (ARS) and acid fuchsin (AF). Within 2.5 minutes, the adsorption efficiencies of ARS and AF were 93.23% and 70.33% respectively, and the corresponding adsorption capacities were 62.17 mg g⁻¹ and 46.9 mg g⁻¹ respectively. The kinetic and thermodynamic analyses of the adsorption process indicated that the adsorption of ARS and AF by La₁₂-g-C₃N₄@β-SiC conformed to the quasi-second-order kinetics and Langmuir adsorption isotherm model, with monolayer chemical adsorption being the main form. In addition, the composite material demonstrated excellent cycling stability and maintained outstanding adsorption performance even after eight repeated uses.