A comparative study for degradation of RB5 dye using Ti/Ir0.15–Ru0.15–Sn0.6–Sb0.1 electrodes fabricated by employing two different thermal decomposition methods

Abstract

A comparison of electrochemical degradation efficiency of Ir- and Ru-based mixed metal oxide electrodes fabricated by two different methods, i.e. polymeric precursor thermal decomposition (PPTD) and standard thermal decomposition (STD), was carried out on Reactive Black 5 (RB5) dye. The electrolysis experiments were performed with 100 mg/L RB5 at initial pH 2, a current density 50 mA/cm2, and 4 mg/L NaCl dosage. The results of the study were evaluated in terms of reduction in colour, COD, and TOC. The result showed higher RB5 degradation rate constants obtained on the PPTD electrode during kinetic study, compared to the STD electrode. A better performance of the PPTD electrode compared to the STD electrode may be attributed to its higher Sn content and its different morphologies observed in characterization using SEM with EDX analysis. Although proven efficient, the service life of PPTD-coated electrode was found only ~ 76 h, compared to ~ 895 h of STD-coated electrode. Experimental results demonstrated that coating method influenced the performance and service life of the electrodes. A comparison of the MTC, ICE, and energy consumption of the two electrodes prepared by STD and PPTD methods demonstrated that PPTD-coated electrodes were more efficient with a shorter life-span.