Photocatalytic activities of hetero-junction semiconductors WO3/SrNb2O6

Hetero-junction photocatalysts WO3/SrNb2O6 were synthesized by a milling–annealing method. The powders were characterized by X-ray diffraction (XRD) and UV–vis diffuse reflection spectroscopy (DRS). Their UV-induced photocatalytic activities were evaluated by the degradation of methyl orange. The results generally show that the hetero-junction semiconductors WO3/SrNb2O6 exhibit better photocatalytic properties than bare SrNb2O6 or WO3. The enhanced performance of WO3/SrNb2O6 is mainly ascribed to the electric field driven electron–hole separations at the interface and in the two semiconductors. An ideal construction scheme for highly efficient combined photocatalysts was proposed. That is, an electron-accepting n-type semiconductor with a high electron conduction ability couples a hole-accepting semiconductor with an open structure and the fair hole conductivity.