Hierarchical polypyrrole encapsulating Bi2O4 to enhance charge separation and light absorption with boosted visible light photocatalytic activity

摘要: Abstract Bi2O4, as a typical visible-light responsive photocatalyst (band gap～ 2.0 eV), has aroused enormous attention in recent years. However, single Bi2O4 the problem of high recombination probability photogenerated electron-hole pairs, which inevitably hampers its photocatalytic performance. Herein, hierarchical polypyrrole encapsulated Bi2O4(Bi2O4@PPy) been constructed via an in-situ vapor-phase polymerization method, producing PPy tightly coated core-shell structure photocatalyst. Thanks to this full coating and structure, charges separation efficiency, light absorption capacity Bi2O4@PPy hybrid are promoted, leading obviously enhanced visible activity. The optimal composite could be obtained through controlling time for 9 h, whose catalytic activity is 2.43 times that alone. active species trapping experiments suggest holes play vital role degradation process. A plausible reaction mechanism over also proposed based on characterization experimental results.