Facile synthesis of porous Bi2WO6 nanosheets with high photocatalytic performance

Compared with the well-known three-dimensional Bi2WO6 nanosheet-assembled nanostructures, the free-standing two-dimensional porous Bi2WO6 nanosheets have seldom been reported. The possible reason is that Bi2WO6 nanosheets with a high surface-to-volume ratio usually tend to self-assemble or aggregate to form microspheres to reduce their surface energy. To prevent their aggregation, in this study, a new and facile self-assembled route, which includes the in situ ion-exchange reaction of Na2WO4 solution with the Bi(NO3)(3) solid powder and the following high-temperature calcination, has been successfully developed to prepare the free-standing porous Bi2WO6 nanosheets. The ion-exchange reaction between the Bi(NO3)(3) solid and Na2WO4 solution can in situ produce amorphous Bi2WO6 nanosheets, while the high-temperature calcination (500 degrees C) causes the formation of homogeneously porous structures in individual nanosheets during their phase transformation from amorphous to crystalline. The resultant porous nanosheets are composed of one-layer Bi2WO6 nanoparticles with a size of 30-50 nm, and there is a strong coupling interface among these nanoparticles. Photocatalytic experimental results suggest that the resultant porous Pt/Bi2WO6 nanosheets show a high photocatalytic performance for the decomposition of phenol solution. Considering their facile preparation, the present synthetic route may provide new insights for the design and fabrication of other nanostructured materials with various potential applications.