Enhanced Photocatalytic Degradation of Phenol by Electron-Directed Movement of Polypyrrole/ZnIn₂S₄ Composites

A PPy/ZnIn₂S₄ (PPy/ZIS) composite photocatalyst has been successfully synthesized using a straightforward in situ growth method and applied to the photocatalytic degradation of phenol. The flaky ZIS material is evenly enveloped around the surface of tubular PPy, forming PPy/ZIS composites. Compared to ZIS and PPy alone, the PPy/ZIS composite exhibits superior electron-hole pair separation performance. Consequently, the PPy/ZIS composite displays a 7.8-fold increase in photocatalytic efficiency compared to pure ZIS nanomaterials, achieving 95% phenol removal within 4 h. The primary active species responsible for phenol degradation are identified as hydroxyl radicals (·OH) and superoxide radicals (·O₂^-). Additionally, an exploration is conducted into the photocatalytic breakdown mechanism of phenol under full spectrum irradiation, specifically for the PPy/ZIS composite. Remarkably, the PPy/ZIS composite demonstrates excellent photostability during cycling tests, underscoring its potential as an effective photocatalytic material for phenol degradation.