Electrochemical Removal of Remazol Black 5 (RB-5) Using SiO2/NiO/Ni Nanocomposite Electrocatalyst Deposited on the Surface of Graphite Electrodes

The SiO2/NiO/Ni nanocomposite electrocatalyst was prepared by the electrodeposition method. The characterization results of SEM-EDX, TEM, FT-IR, and XRD showed that SiO2/NiO/Ni nanocomposite electrocatalyst was deposited on the graphite surface. Furthermore, the G/SiO2/NiO/Ni nanocomposites had higher electrocatalytic activity and surface area than that of graphite. The optimal condition for electrochemical removal of RB-5 using G/SiO2/NiO/Ni electrode was reached at 0.05 M NaCl and pH 4 for 60 min with 100% absorbance removal efficiency. The highest COD removal efficiency of 92.85% was obtained with G/SiO2/NiO/Ni, while the lowest of 67.57% was achieved using graphite electrodes. Based on the LC-MS analysis results, the electrochemical removal of RB-5 produced naphthalene, aromatic, and aliphatic compounds.