Polypyrrole/Bi2WO6 composite with high charge separation efficiency and enhanced photocatalytic activity

The recombination of photogenerated electrons and holes is a crucial factor that limits the efficiency of photocatalysis and dye-sensitized solar cells. Conducting polymers are known to have high charge carrier mobility. Herein, a polypyrrole (PPy)/Bi₂WO₆ composite with promoted charge separation efficiency was designed by a “photocatalytic oxidative polymerization” method. The photo-degradation of a typical model pollutant, phenol, demonstrated that the PPy/Bi₂WO₆ composite possessed significantly enhanced photo-activity than pure Bi₂WO₆ under simulated sunlight irradiation. The higher photo-activity was attributed to the synergetic effect between PPy and Bi₂WO₆. The photogenerated holes on the valence band of Bi₂WO₆ could transfer to the highest occupied molecular orbital of PPy, leading to rapid photoinduced charge separation and enhancing the photocatalytic activity. This work provided a new concept for rational design and development of highly efficient polymer-semiconductor photocatalysts for environmental purification under simulated sunlight.