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.