Adsorption of azo dyes and Naproxen by few-layer MXene immobilized with dialdehyde starch nanoparticles: Adsorption properties and statistical physics modeling

Novel Eco-friendly composite materials (DSP-M) were organized by combining few-layer MXene with the hydrophilic biomaterial dialdehyde starch nanoparticles (DASNP) and immobilizing DASNP on the surface of few-layer MXene by the dialdehyde-based cross-linking method. In addition to the study on the adsorption performance and mechanism of prohibited dyes (Rhodamine B, RB and Congo Red, CR) in food industry, the removal and mechanism of non-steroidal anti-inflammatory drug (Naproxen, NPX) residues in pharmaceutical field were also investigated. DSP-M was physiochemically characterized via series of analytical techniques and the dye adsorption isotherms at three temperatures were quantified. The results show that DSP-M exhibited excellent adsorption performance for all three selected adsorbates, and the Langmuir maximum monolayer adsorption capacity were 678.19 mg/L for RB, 754.41 mg/L for CR and 166.71 mg/L for NPX, respectively, and it agreed well with the Langmuir, pseudo–second order and intraparticle diffusion models. The statistical physics model was employed to further explore the adsorptive mechanism. The characteristics of DSP-M after adsorption and the simulation results indicate that the removal of RB, CR and NPX by DSP-M was mainly a physical adsorption process involved with hydrogen bonding, electrostatic force and van der Waals force.