Evaluation of in situ water electrochemical disinfection using novel carbon-based and noble metal electrodes

In this study, the morphology, chemical composition, and electrochemical characteristics of three carbon-based and three noble metal/alloy electrodes were evaluated. Measurement of free chlorine production was carried out using iodine–starch method. Measurement of hypochlorite production was performed using N,N-diethyl-p-phenylenediamine (DPD). The electro-catalytic activity of the electrodes was characterized using cyclic voltammetry (CV). Among the noble metals, the gold–palladium alloy electrode showed the best catalytic performance. Among the carbon-based electrodes, TiC showed the best catalytic performance. Scanning electron microscopy (SEM) images before and after reaction confirms the stability of the TiC electrode, proving its potential for long-term use. The chemical structure of the electrodes was characterized using X-ray photoelectron spectroscopy (XPS) and this showed that carbon electrodes present a trace graphene oxide structure (sp3 orbitals C–OH/C–O). Moreover, the modification of porous carbon by vacuum-assisted TiO2 impregnation indicates that the electronic state of TiC did not change due to impregnation with TiO2. In summary, the TiC carbon-based electrode shows high stability and potential for long use.