Molecular-level insight into CNT-decorated La2Mo4O15 nanocomposites for antimony adsorption from aqueous media: Machine learning simulation, interfacial behavior, and recyclability in supercapacitor electrolytic environments

Abstract

The development of multifunctional materials capable of addressing both environmental remediation and energy storage is essential for advancing sustainable technologies. In this study, La₂Mo₄O₁₅/carbon nanotube (LaMo/CNT) nanocomposites were prepared and investigated as adsorbent material for Sb(III) removal and high-performance supercapacitor electrodes. The nanocomposites demonstrated removal efficiency of 88.7 % for Sb(III), with adsorption kinetics following a pseudo-II order model. The adsorption performance was governed by synergistic interactions including electrostatic attraction, hydrogen bonding, and inner-sphere complexation. Machine learning models (ANN, NLR, and SVR) were employed to infer Sb(III) adsorption efficacy, with the ANN model showing superior predictive accuracy. High-resolution X-ray photoelectron spectroscopy revealed chemical state evolution of La, Mo, Sb, and O before and after Sb(III) adsorption and thermal activation. The appearance of distinct Sb 3d peaks confirmed successful immobilization, while post-activation spectral shifts indicated partial oxidation to Sb(V), consistent with Sb-O-M (M = La, Mo) coordination and enhanced redox activity. The Sb-adsorbed nanocomposites were repurposed as supercapacitor electrodes, delivering a specific capacitance of 824.44 F/g at 1.5 A/g and surpassing the performance of pristine LaMo/CNT (783.21 F/g). The assembled symmetric device retained 90.2 % capacitance after 15,000 cycles and achieved an energy density of 73.53 Wh/kg at 750 W/kg. This work proposes a sustainable waste-to-energy pathway by integrating machine learning, interfacial chemistry, and multifunctional design for environmental and energy applications.