Performance optimization of CuO-ZnO ceramic electrode on the electrocoagulation of wastewater

Abstract

Copper oxide (CuO) and zinc oxide (ZnO) were used as a matrix and reinforcement in the compression molding technique to produce conductive ceramic electrodes. CuO-ZnO-based ceramic composites were fabricated through conventional pressing with CuO:ZnO ratios of 75 %:25 %, 80 %:20 %, 85 %:15 %, 90 %:10 %, and 95 %:5 %. CuO and ZnO powders were sieved, dried, mixed, and then compressed at 300 MPa for 10 min to form a pellet before being burned for 3 h at 800, 900, and 1000 °C in a furnace. The sample's density, porosity, and electrical conductivity were measured. In addition, SEM, XRD analysis, and palm oil wastewater electrocoagulation were carried out. The optimal density value of CuO-ZnO-based ceramic composites ranged from 8.564 × 10³ to 9.205 × 10³ kg m⁻³. The optimal composition of the CuO:ZnO in the synthesized composites, namely 95 %:5 %, yielded the lowest porosity values (12.1 %-35.4 %), while the 75 %:25 % composition produced the highest porosity values (20.8 %–88.3 %). The optimum porosity value (12.1 %) was obtained by CuO:ZnO composite composition of 95 %:5 % with a sintering temperature of 1000 °C. This composite also generates a conductivity value of 1.019–16.897 S/m. The interaction of Zn²⁺ ions from ZnO crystals with CuO crystals increases the size of CuO and ZnO crystals, as determined by XRD analysis. Based on the findings of this study, CuO-ZnO ceramic electrodes could be utilized in industrial wastewater treatment as the water quality test result met the requirements of Minister of Environment Decree No. 51/MENLH/10/1995.