Photocatalytic activity of Pt-modified Bi2WO6 nanoporous wall under sunlight

In this work, Bi 2 WO 6 nanoporous wall was synthesized by using Bi 2 O 3 as template and Bi source. Pt nanoparticles whose average size is about 8 nm were further immobilized on the Bi 2 WO 6 nanoporous wall via a simple chemical reduction process. Their photocatalytic activity and the effect of Pt modification were studied by analyzing the degradation of an organic dye, rhodamine 6G (Rh6G), under simulated sunlight. It was found that the photocatalytic ability of Bi 2 WO 6 nanoporous wall was enhanced by introducing Pt nanoparticles. Bare Bi 2 WO 6 shows a degradation efficiency of 78 % after 1 h, while the degradation efficiency of 5 wt% Pt-modified Bi 2 WO 6 was 99 %, and on further increasing the Pt content in the as-prepared Pt-modified Bi 2 WO 6 catalysts, their photocatalytic ability will decrease. The optimal catalyst could be reused without any decrease for five cycles, which may due to Pt be able to help trap the conduction band electrons in the absence of Rh6G. A possible photocatalytic mechanism was proposed and further proved by transient photocurrent response experiment.