In2S3/HAp nanocomposite: a comprehensive study on synthesis, structural insights, and high-performance adsorption of Methyl Red dye in water treatment applications

Abstract

ABSTRACT This research aims to show the synthesis, characterisation, and adsorptive performance of a novel In2S3/HAp nanocomposite, in which In2S3 nanoparticles are anchored onto hydroxyapatite (HAp) produced from fish scales. The nanocomposite adsorbs Methyl Red (MR) dye from aqueous solutions with surprising efficiency. The structural and chemical properties of the In2S3/HAp nanocomposite were determined using a variety of analytical techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Comprehensive isotherm and thermodynamic analyses demonstrated a significant adsorption capacity of 331.91 mg g−1, yielding a superior removal efficiency of 91.78% for 20 mg L−1 MR dye utilising just 10 mg (0.2 g L−1). Statistical physics modelling (SPM) gave quantitative insights into adsorption, revealing critical parameters such as adsorption site density, saturation adsorption capacity, and adsorption energies. The study found that MR dye adsorption happened in both parallel and non-parallel processes, highlighting the complex nature of the interaction between dye molecules and the nanocomposite surface. The adsorption process was discovered to be exothermic. Furthermore, reusability studies revealed that the nanocomposite may be reused up to 5 times with just a 13% drop in efficiency, confirming its promise for practical applications. The nanocomposite functioned consistently across several water matrices, demonstrating versatility in various water treatment applications. Finally, the In2S3/HAp nanocomposite appears as a viable and long-lasting option for MR dye removal, as evidenced by extensive characterisation, statistical modelling, and exceptional performance. These findings highlight its potential for larger environmental remediation applications in treating dye contamination in bodies of water.