Synthesis of flower-like Ag2O/BiOCOOH p-n heterojunction with enhanced visible light photocatalytic activity

摘要

The development of efficient semiconductor heterojunction photocatalysts has drawn much attention. Herein, we have reported a kind of flower-like Ag2O/BiOCOOH p-n heterojunction as a novel and efficient visible-light-driven photocatalyst. The Ag2O/BiOCOOH heterojunctions have been successfully prepared via a solvothermal precipitation-deposition method. They consist of flower-like BiOCOOH microspheres (diameters: 1-2.5 mu m) decorated with AgO nanoparticles (size: similar to 14nm). In addition, optical characterization reveals that they have broad visible-light photo-absorption. Importantly, under visible-light irradiation (lambda > 400 nm), all Ag2O/BiOCOOH heterojunctions exhibit enhanced photocatalytic activity than pure BiOCOOH or Ag2O for the degradation of rhodamine B (RhB) dye and para-chlorophenol (4-CP). Especially, the Ag2O/BiOCOOH heterojunction with the Ag/Bi molar ratio of 0.2/1 shows the highest photo catalytic activity, which is even higher than the activity from the mechanical mixture (8 wt%Ag2O + 92 wt% BiOCOOH). This enhanced photocatalytic performance could be predominantly attributed to the efficient separation of photogenerated electron-hole pairs. The photogenerated holes (h(+)) and superoxide radical anions ((.)0(2)(-)) have been found to be the main reactive species responsible for the photodegradation of RhB dye in aqueous solution. Therefore, the Ag2O/BiOCOOH p-n heterojunction has great potential to be used as a kind of efficient visible-light-driven photocatalyst. (C) 2016 Elsevier B.V. All rights reserved.