Enhancement of Visible-Light Photocatalysis by Coupling with Narrow-Band-Gap Semiconductor: A Case Study on Bi2S3/Bi2WO6

To overcome the drawback of low photocatalytic efficiency brought by electron–hole recombination and narrow photoresponse range, we designed a novel Bi2S3/Bi2WO6 composite photocatalyst. The composite possesses a wide photoabsorption until 800 nm, which occupies nearly the whole range of the visible light. Compared with bare Bi2WO6, the Bi2S3/Bi2WO6 composite exhibits significantly enhanced photocatalytic activity for phenol degradation under visible light irradiation. On the basis of the calculated energy band positions, the mechanism of enhanced photocatalytic activity was proposed. The present study provides a new strategy to design composite materials with enhanced photocatalytic performance.