Exploring sustainable water treatment: comprehensive analysis of an NZS-D nanocomposite for enhanced dye adsorption

Abstract

In this study, an innovative hybrid nanocomposite, abbreviated as NZS-D, was developed by incorporating nickel and zinc binary sulphide nanoparticles into the organic framework of date seed grains through a straightforward co-precipitation technique. The synthesized NZS-D was comprehensively characterized using various spectroscopic techniques which confirmed the presence of abundant functional groups on the NZS-D surface, porous morphology, and grain size range of 70–90 nm. The NZS-D was investigated for its capability to remediate polluted water through adsorption of two model dyes, one cationic, i.e., Nile blue, and the other anionic, i.e., Congo red, from simulated wastewater in the batch method. The process was investigated to check the influence of water pH, temperature, dye concentration, NZS-D dosage, and contact time, on the sorption capacity. Remarkably, the maximum sorption capacity (Q_max) reached to 208.333 and 121.951 mg g⁻¹ for Congo red and Nile blue, respectively, under optimized conditions. The sorption was found to be thermodynamically feasible, physicochemical process governed by the weak Van der Waals forces or electrostatic interaction between the functional groups at the NZS-D surface and the dye molecules in water. The mechanisms of the preparation of NZS-D and the sorption process have been thoroughly investigated and explained.