Synthesis, Characterization, and Cyanide Photodegradation Over Cupric Oxide-Doped Zinc Oxide Nanoparticles

Abstract

A simple, rapid, inexpensive, room-temperature wet chemical route for synthesizing CuO-doped ZnO nanoparticles was established. Undoped and CuO-doped ZnO photocatalysts, with 1, 2, 3, and 4 wt.% of CuO, were prepared by using cyclohexylammine for coprecipitation of the metals from their aqueous solutions, followed by calcination at 500°C. The photocatalysts were characterized by ICP elemental analysis, UV-Vis absorption spectroscopy, XRD, SEM, EDX, and TEM. The synthesized materials were tested for oxidative photodegradation of cyanide in aqueous medium at room temperature. The undoped material exhibited an activity of 56% cyanide removal efficiency. Doping of ZnO with 1 and 2 wt.% CuO dramatically enhanced the photocatalytic activity to 89% and 93 %, respectiviely, while to 97% for both 3 and 4 wt.%. This improvement in photocatalytic activity can be attributed to the reduction of ZnO band gap and the increase in charge separation on the surface of photocatalyst particles.