Tannic Acid-Mediated Silver Prussian Blue Nanocomposites: Synergistic Peroxymonosulfate Activation Mechanism and p-Chlorophenol Degradation Performance

Prussian blue analogues (PBAs), as promising peroxymonosulfate (PMS) activators for water remediation, typically suffer from issues such as agglomeration, morphological inconsistency, and insufficient active site exposure, limiting their practical application. Here, we developed a tannic acid-mediated synthesis of silver-doped PB nanocomposites (TA-AgPB) for efficient activation of PMS and rapid degradation of p-chlorophenol (4-CP). The TA-AgPB system achieved 99% degradation of 4-CP within 10   minutes, exhibiting a kinetic constant 2.1 times higher than that of unmodified AgPB, and exhibited superior adaptability in pH 5.0-9.0. Furthermore, TA-AgPB demonstrated marked performance enhancement, with PMS utilization and mineralization rates increasing from 51.6% and 41.5% to 90.4% and 68.2%, respectively. Ag plays an indispensable role in the activation process. The introduced Ag not only synergizes with Fe centers to facilitate electron transfer but also modulates the electronic structure of the active sites to promote the generation of reactive oxygen species (ROSs). Tannic acid, as a multifunctional green modifier, possesses abundant phenolic hydroxyl groups that not only effectively coordinate with metal ions to suppress Ag + leakage and particle aggregation but also facilitate the formation of uniform nanostructures, significantly increasing active site exposure. Quenching experiments, electron paramagnetic resonance (EPR) and electrochemical studies revealed the synergistic generation of •OH, SO 4 •⁻ , O 2 •⁻ and 1 O 2 , constitutes the primary mechanism for 4-CP degradation. DFT calculations confirmed thermodynamically favorable degradation pathways. This work provides a polyphenol-mediated synthesis strategy for designing stable and efficient PBAs catalysts, advancing their practical application in water purification.