Construction of a novel ternary synergistic CuFe 2 O 4 -SnO 2 -rGO heterojunction for efficient removal of cyanide from contaminated water.

Many industrial effluents release cyanide, a well-known hazardous and bio-recalcitrant pollutant, and thus, the treatment of cyanide wastewater is a major challenge. In the current study, a CuFe 2 O 4 -SnO 2 -rGO nanocomposite was synthesized to remove cyanide from an aqueous system. The structural and morphological characterizations of the nanomaterials were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive spectra (EDX) analysis. The results revealed that almost 97.7% cyanide removal occurred using the nanocomposite at an initial concentration of 100 mg L -1 within 1 h. The experimental data were fitted to various adsorption models, among which the Langmuir model fitted the data very well, confirming the monolayer adsorption process. The kinetic investigation revealed that the cyanide adsorption process followed a pseudo-second-order kinetic model, indicating a chemisorption process with a high cyanide adsorption capacity of 114 mg g -1 . The result of the intraparticulate diffusion model fitting revealed a decreasing slope value ( K ) from stage 1 to stage 2, indicating that external mass transfer is the predominating step. Moreover, the CuFe 2 O 4 -SnO 2 -rGO nanocomposite shows excellent reusability.