Synthesis of CuOx nanostructures in novel electrolytes under hydrodynamic conditions for photoelectrochemical applications

Abstract

In this work, CuO_x (x = 1 and 2) nanostructures have been synthesized by electrochemical anodization in ethylene glycol based electrolytes using oxalic acid or NaF (with or without NaOH) as complexing agents. The influence of hydrodynamic conditions and time during anodization of copper have also been evaluated. A comprehensive morphological, structural, electrochemical and photoelectrochemical characterization of the nanostructures has been performed. The results revealed the convenient use of oxalic acid and 250 rpm for 5 minutes during electrochemical anodization to obtain homogeneous CuO_x nanostructures formed by spheres with Cu₂O as a predominant phase. Using this nanostructure as a photocathode for N₂O photoelectron-reduction, almost 100% of N₂O removal was achieved after 1 h, showing the improvement of the photoelectrochemical approach vs. the photo or the electro performance.