Thermal preparation and characterization of nanodispersed copper-containing powders produced by non-equilibrium electrochemical oxidation of metals

© 2020 Elsevier Masson SAS Physicochemical properties of copper, aluminum and cadmium oxides determine their application in different ways. Electrochemical metal oxidation using alternating current (AC) influences the band gap of prepared copper-containing oxide materials and result in a blue shift. The use of alternating current provides sufficient conditions responsible for nanosized materials formation (grain size: 20–30 nm for separate copper oxidation, 15–20 nm for joint copper and aluminum oxidation). In the present work, XRD and DSC/DTG, SEM analyses were used to characterize the electrolysis products. A decrease of the thermal transformation temperature (Cu2O oxidation at 260°С, copper-aluminum layered double hydroxide (Cu–Al/LDH) decomposition at 140°С) of the products of both separate copper oxidation and joint copper and aluminum (or cadmium) oxidation was established when compared with those of the same oxides prepared by the usual methods. Solution aging of these products after joint electrochemical oxidation of copper and aluminum results in the transformation of Cu2O–AlOOH to Cu–Al/LDH. Products of the joint oxidation of copper and cadmium consist of oxides and hydroxides of copper and cadmium (γ-Cd(OH)2, Cu(OH)2, β-Cd(OH)2, CdО and Cu2O), which are not capable to form LDH. The synthesized copper-containing mixed metal oxide will be investigated elsewhere to obtain their structural characterization and operating performance in catalytic, photocatalytic and other applications