Synthesis of one-dimensional WO3-Bi2WO6 heterojunctions with enhanced photocatalytic activity

WO3-Bi2WO6 heterostructures were synthesized by a facile hydrothermal method using WO3 nanorods and Bi(NO3)(3) solution as raw materials. The Bi2WO6 nanosheets uniformly anchored onto the surface of the WO3 nanorods. The photocatalytic activity of the samples was assessed for degradation of rhodamine B (RhB) and phenol under solar light irradiation. The WO3-Bi2WO6 heterostructures showed higher photocatalytic activities than pure WO3 and Bi2WO6. As the content of Bi2WO6 increased, the photocatalytic activity of the WO3-Bi2WO6 heterojunction was enhanced and the optimal sample was WO3-Bi2WO6 with a nWO(3) : nBi(3+) mole ratio of 5 : 3. The efficient separation of electron-hole pairs because of the staggered band potentials between WO3 and Bi2WO6 may account for the higher photoactivity of WO3-Bi2WO6 hybrid structures. Radical scavenger experiments indicate that holes (h(+)) and superoxide radicals (O-center dot(2)-) were the main active species for RhB degradation during the photocatalytic process.