Effects of twelve sodium dodecyl sulfate (SDS) on electro-catalytic performance and stability of PbO₂ electrode

To improve the electro-catalytic performance and stability of PbO₂ electrode in organic wastewater treatment, sodium dodecyl sulfate (SDS, a typical anionic surfactant) modified PbO₂ electrode was successfully synthesized by electro-deposition method. The morphology, crystal phase, electro-catalytic performance, safety assessment and stability were studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), Acid red G (ARG) degradation, inductively coupled plasma atomic emission spectroscopy (ICP-AES) detection and the accelerated life test, respectively. In addition, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) were applied. The results showed that SDS could obviously refine the coating particles, increase the oxygen evolution potential (OEP) and accelerate charge transfer. After modified with SDS, the electro-catalytic performance and stability of PbO₂ electrode were greatly improved. The PbO₂ electrode modified at 5.0 vt% volume fractions of SDS (PbO₂-SDS(5.0)) exhibited the highest ARG decolorization rate of 83.5% and the largest COD removal rate of 53.9%, respectively, which could be attributed to the highest OEP and massive adsorbed hydroxyl oxygen (O_ad). Besides, PbO₂-SDS(5.0) electrode showed a high reusability for ARG degradation and the accelerated service life could reach 348 h, which was almost 3.6 times longer than that of PbO₂ electrode (96 h).