Orange Pomace Facilitated Synthesis of Cu₂O/ZnO Nanocomposites for Visual and Optical Sensing of Silver Ions in Water for Environmental Remediation

Abstract

The presence of silver ions at toxic concentrations in wastewater has provoked many scientists to design novel methods to detect silver ions in water. Employing agro‐waste to design nanomaterials has incited the use of orange pomace to design fruitful and biocompatible nanomaterials for endorsing sustainable and green methods. Herein, we report a sensitive and selective colorimetric detection of silver ions employing biogenically synthesized Cu2O/ZnO nanocomposites (NCs). The Cu2O/ZnO NCs were fabricated using orange pomace (OP) holistically acting as a stabilizing and reducing agent. Sensing ability of Cu2O/ZnO NCs synthesized via greener route for the presence of different metal ions such as Na+, Ca2+, Cd2+, Sr2+, Ag+, Ni2+, Fe2+, Pb2+, Mg2+, and K+ has been examined at room temperature. A naked eye colour change form slight yellowish to black was noticed in case of silver ions, this is confirmed by the shifting of maximum wavelength from 453 nm to 362 nm. Thus, in this work Cu2O/ZnO NCs was demonstrated as an extremely specific and selective colorimetric nanosensor for silver ions in water and showed a good linearity over the range of 20 μM–2 mM and a limit of detection (LOD) of 13.1 μM. The green fabrication of nanosensor for silver ions further maintain the sustainability of environment and encourage the researchers for greener fabrication of colorimetric sensors.