Mg Al-layered double hydroxide (LDH)-assisted multiwalled carbon nanotube (MWCNT) grafting on poly-2-aminothiazole (PAT) /chitosan (CS)-blend matrix for Cd2+ removal and 4-nitrophenol reduction

Abstract

The present study evaluated the performance of multiwalled carbon nanotube (MWCNT)@MgAl-layered double hydroxide (LDH) nanoparticles loaded on poly-2 aminothiazole (PAT)/chitosan (CS) matrix to remove Cd2+ ions from aqueous solution. We created a new PAT-based adsorbent by mixing PAT and CS nanoparticles, and surface modification by MWCNT@LDHs. For preparing the adsorbent, first, the PAT surface was modified by CS as an excellent candidate with a large number of –OH functional groups for interfacial adhesion improvement of the composite and enhancing the adsorption of the polymer. Then, to the homogeneous distribution of MWCNT in the matrix (CS/PAT), the surface of the functionalized MWCNT (MWCNT-COOH) was covalently modified by LDHs. Finally, the nanocomposite (NC) films were fabricated by ultrasonication using various loadings (30–70 wt %) of MWCNT@LDH. The prepared films were labelled CP-30%, CP-50%, and CP-70%. By adding MWCNT@LDH to the matrix network, the removal efficiency was increased significantly compared to CS/PAT. The influence of heavy metal ion concentration, pH, temperature, adsorbent dosage, and contact time on the adsorption. The maximum absorption capacity of 1106.19 mg/g was measured for Cd2+. The pseudo-first-order kinetics (PFO) and the Langmuir model were selected as the best models for the adsorption process. Also, the NC was successfully tested for p-nitrophenol (p-NP) reduction in the presence of NaBH4. The reaction was nearly completed in 6 min. Studies showed that the fabricated NC could be reused for three consecutive cycles.