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Molybdenum trioxide/polypyrrole (MoO3/Ppy) nanocomposite was prepared via oxidative polymerization of pyrrole monomer with MoO3 nanoparticles. The adsorption of Cd+2 and nile blue (NB) onto the nanocomposite was investigated in terms of various process parameters. The characterization of MoO3/Ppy nanocomposite was carried out by Fourier transform‐infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and energy dispersive X‐ray spectroscopy. Higher R2 (0.992–0.997 for Cd+2 and 0.997–0.998 for NB) and lower standard error of estimation values (1.04–1.82 for Cd+2 and 0.87–1.07 for NB) for Freundlich isotherm highlighted the multilayer adsorption onto heterogeneous nanocomposite surface. The higher Qm values at 323 K for Cd+2 (181 mg/g) and NB (189 mg/g) compared to many reported adsorbents proved the adsorptive superiority of MoO3/Ppy. The energy of adsorption (E) values from Dubinin–Radushkevich model was 1.26–1.38 and 1.36–1.44 kJ/mol for Cd+2 and NB, respectively, suggesting physical adsorption. Pseudo‐second order kinetic model governed the adsorption of Cd+2 and NB with intraparticle and liquid film diffusion controlling the mechanism. The negative ΔG values (8.4–9.4 kJ/mol) and positive ΔH values (2.5–6.1 kJ/mol) implied spontaneous and endothermic adsorption process. The positive ΔS values (0.036–0.048 kJ/mol/K) indicated increased randomness at MoO3/Ppy‐Cd+2 or NB interface. The MoO3/Ppy nanocomposite proved to be suitable and efficient adsorbent for sequestering of Cd+2 and NB from aqueous solution.

Herein, a simplistic redox polymerization strategy was utilized for the fabrication of a poly­(methacrylic acid)/montmorillonite hydrogel nanocomposite (PMA/nMMT) and probed as a sorbent for sequestration of two pharmaceutical contaminants, viz., amoxicillin (AMX) and diclofenac (DF), from wastewater. The synthesized hydrogel nanocomposite was characterized by the Fourier transform infrared, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy–energy dispersive X-ray spectroscopy, and transmission electron microscopy techniques to analyze structural characteristics and sorption interactions. The efficacy of PMA/nMMT was thoroughly investigated for the sequestration of AMX and DF from the aquatic phase with a variation in operative variables like agitation time, sorbent dosage, pH, and initial sorbate concentration. The reaction kinetics was essentially consistent with the pseudo-second-order model with rate dominated by the intraparticle diffusion model as well as the film diffusion mechanism. The Freundlich isotherm appropriated the equilibrium data over the entire range of concentration. Thermodynamic investigation explored the spontaneous and endothermic nature of the process. The most possible mechanism has been explained, which includes electrostatic interaction, hydrogen bonding, cationic exchange, and partition mechanism. Economic feasibility, better sorption capacity (152.65 for AMX and 152.86 mg/g for DF), and efficient regeneration and reusability even after four consecutive sorption–desorption cycles ascertained PMA/nMMT as a potential sorbent for AMX and DF uptake from the aqueous phase.

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