A Review on the Effect of the Surfactants in Anodic Deposition Process of Lead Dioxide Coating

Lead dioxide (PbO2) anodes are widely used in electrochemical oxidation and wastewater treatment; however, their performance is strongly governed by surfactant-assisted electrodeposition. This review summarizes advances from 2010 to 2025 on how anionic, cationic, nonionic, and zwitterionic surfactants tailor the nucleation, crystal growth, and functional properties of PbO2 coatings. Representative additives—including SDS, SDBS, CTAB, PEG, Triton X-100, gelatin, and fluorinated surfactants—demonstrate distinct mechanisms based on head-group charge, hydrophobic chain length, and critical micelle concentration. Comparative analysis shows that appropriate surfactant selection can substantially reduce film porosity, refine grain size, enhance coating compactness, and decrease charge-transfer resistance, thereby improving electrocatalytic activity toward oxygen evolution and organic pollutant degradation. Particular emphasis is placed on high-impact systems such as SDS/SDBS for grain refinement, CTAB and STAB for compact β-PbO2 formation, and PEG or Triton X-100 for smoothing and defect suppression. Despite significant progress, key challenges remain, including limited mechanistic insight into surfactant–ion interfacial interactions and the minimal use of environmentally benign biosurfactants. Overall, optimizing surfactant chemistry represents a scalable and effective strategy for engineering next-generation PbO2 anodes with improved durability and catalytic efficiency for energy and environmental applications.