Synthesis and characterization of copper oxide nanoparticles by electrochemical method: investigation of electrolyte composition

Copper oxide is obtained by various methods, including electrolysis, recovery of copper salts or copper oxide, thermal oxidation and hydrothermal treatment. Electrochemical method is very interesting due to its low cost, low temperature, ease of operation, high purity and compatibility with the environment. In this research, the effects of NaCl, Na2SO4 and CTAB (cetyltrimethylammonium bromide, C19H42BrN) electrolytes on the synthesis of Cu2O nanoparticles by electrochemical method were investigated. Changes of NaCl in three values of 58.5, 117 and 175.5 (g/lit); changes of Na2SO4 in concentrations of 24, 32 and 48 (g/lit) and changes of CTAB in the range of 2, 4, 6 and 15 (g/lit) were selected. The current density and temperature were fixed and equal to 0.4 (amps/cm2) and 70°C, respectively, and the fixed distance between the cathode and the anode was considered to be 2.5 cm. FESEM and XRD were used to observe the morphology of the samples and identify the composition and determine the particle size. The results showed that by increasing the concentration of NaCl and Na2SO4 electrolyte, the purity of Cu2O increased. The size of Cu2O crystals was below 100 nm and the formation of Cu2O was polycrystalline. Also, high concentration of NaCl gave better results compared to Na2SO4. CTAB effectively prevents the growth of Cu2O nanoparticles and the particle size was inversely related to the increase of CTAB. The best result was obtained in the sample with 4 (g/lit) CTAB and 175(g/lit)NaCl. Cu2O nanoparticles with high purity and crystal size of 27.87 nm were produced.