A facile one-pot synthesis of Ag2Te nanoparticles and the fabrication of nanocomposites for the removal of chromium (VI) in wastewater

Abstract

The sol–gel method has been used successfully for the preparation of crystalline PVA-Ag2Te nanoparticles at room temperature using water as a solvent, PVA as a capping agent, sodium borohydride as a reducing agent, telerium, and silver nitrate as a source of silver. The synthesized PVA-Ag2Te were then incorporated with chitosan to form the nanocomposites for the removal of Cr(VI) ions from wastewater. A blue shift in the wavelength was observed with an energy band gab between 2.76 eV and 2.82 eV when the PVA was added into the nanoparticles. The morphology and structural studies of the particles were carried out using transmission electron microscopy (TEM) and powder-X-ray diffraction (XRD). The XRD patterns of the Ag2Te projected a pure monoclinic phase whereas TEM images showed agglomerated spherical shaped particles that were improved when the stabilizers was introduced into the nanomaterial with the average particle sized between 8.77 and 9.12 nm. The adsorption process was able to verify that the parameters such as pH, contact time, and initial concentration had a huge impact on water treatment processes. The essential parameters of Langmuir and Freundlich adsorption isotherms were successively utilized to analyze the adsorption mechanism. This was accomplished by combining the isotherms equation with mass conservation of solute before and after adsorption.