Enhancement of visible-light photocatalysis by coupling with narrow-band-gap semiconductor: A case study on Bi ₂S ₃/Bi ₂WO ₆

To overcome the drawback of low photocatalytic efficiency brought by electron-hole recombination and narrow photoresponse range, we designed a novel Bi ₂S ₃/Bi ₂WO ₆ composite photocatalyst. The composite possesses a wide photoabsorption until 800 nm, which occupies nearly the whole range of the visible light. Compared with bare Bi ₂WO ₆, the Bi ₂S ₃/Bi ₂WO ₆ 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.