Enhanced visible light photocatalytic activity of Bi2WO6 via modification with polypyrrole

► Novel PPy/Bi2WO6 composite photocatalysts were synthesized by 'in-situ' deposition oxidative polymerization of pyrrole. ► PPy on the surface of Bi2WO6 could narrow the band gap and inhibit the recombination of holes and electrons. ► PPy showed great influences on improving the photocatalytic activity of Bi2WO6. ► The mechanism for enhanced photocatalytic activity of PPy/Bi2WO6 photocatalyst was discussed.