Reactive Black 5 Removal by Electrochemical Oxidation Using Titanium Dioxide Nanoparticle Electrodes

Abstract

Reactive Black 5 (RB5) is a commonly employed azo dye that is widely utilized in textile dyeing procedures due to its intense black color and simple application. Wastewater containing this dye may be released into the environment, consequently causing harm to the environment and the organisms therein. Hence, there is a need to treat wastewater containing pollutants such as RB5. Electrocatalysis is an effective method to degrade organic pollutants. Titanium dioxide (TiO2) nanoparticles are examples of electrocatalysts and have demonstrated superior efficacy in the degradation of a variety of organic compounds compared to other investigated electrocatalysts. However, there is a lack of comprehensive knowledge regarding the electrocatalytic degradation efficiency, and reaction kinetics of RB5 degradation using TiO2 nanoparticles. This work aimed to investigate the potential of TiO2 nanoparticle electrodes for electrocatalytic degradation of RB5 dye in wastewater. Electrolysis experiments and analytical measurements were conducted to determine optimal conditions of parameters such as voltage, electrolyte composition, and concentration, as well as pH. Different RB5 concentrations were used to determine the suitable environment for degradation. Optimization revealed that the ideal voltage for RB5 removal was 6 V. Sodium chloride (NaCl), and sodium sulfate (Na2SO4) were used as electrolytes, with NaCl outperforming Na2SO4 in RB5 removal efficiency. The ideal NaCl concentration and pH for RB5 removal were found to be 0.05 M and 7, respectively. The range of system adaptation which yielded the highest removal efficiency was found to be 100 mg/L of RB5. Under these optimized conditions, the apparent rate constant decreased over time, indicating effective degradation.