Synthesis, Characterization and Potential Application of Functionalised Binary Metallic Sulphide for Water Reclamation

Abstract

The present paper highlights the synthesis of novel Citric acid functionalized-Nickel-Cobalt-Sulphide nanoparticles, abbreviated as Ni-Co-S@Ct, via simple co-precipitation method. The prepared nanoparticles have been characterized using several analytical techniques, like XRD, HR-TEM, TGA, HR-SEM, FT-IR, XPS and BET and zeta potential measurements. The prepared Ni-Co-S@Ct nanoparticles have been investigated for the adsorptive removal of different types of pollutants, namely, cationic and anionic dyes, and arsenic ions and interestingly all of these pollutants were removed with high efficiency. The equilibrium sorption capacity of Ni-Co-S@Ct has been found 90.91 mg/g for Methylene blue, 232.55 mg/g for Crystal violet, 357.14 mg/g for Nile blue, 142.9 mg/g for Congo red, 1111 mg/g for As(III) and 2000 mg/g for As(V). The sorption data for these pollutants fitted well to Freundlich and Temkin isotherms which showed the attachment of these ions/molecules to the specific sites at Ni-Co-S@Ct heterogeneous surface. The kinetics of sorption process was explained using the pseudo-second order model which suggested pollutant ion attachment at specific sites at the surface of Ni-Co-S@Ct. The FT-IR and Zeta potential analysis led to the conclusion that electrostatic interaction and metal complexation might be the prominent pathways adopted by the Ni-Co-S@Ct for the sorption of dyes and arsenic ions. The nanomaterials was further investigated for the removal of dyes from the mixture of dyes and the results have been quite promising as the material was found effective for elimination of four dyes simultaneously. Therefore, the high adsorption capacity, low-cost and facile synthesis, takes Ni-Co-S@Ct a step ahead in environmental remediation and wastewater treatment technology.