Synthesis of hierarchical Bi2O3/Bi4Ti3O12 p-n junction nanoribbons on carbon fibers from (001) facet dominated TiO2 nanosheets

A novel hierarchical photocatalyst of Bi2O3/Bi4Ti3O12 p-n junction nanoribbons (NRs) on carbon fibers has been successfully fabricated from the precursor of (001) facet dominated TiO2 nanosheets (NSs), which provide well-shaped templates. The dominant (001) facets of the TiO2 precursor diminished slower than the (101) facets during the hydrothermal process. Single crystallized p-type Bi2O3 and n-type Bi4Ti3O12 coexist, forming p-n junctions within one NR. This hierarchical nanostructure exhibits markedly improved photocatalytic activity for degradation of methyl orange. The improvement can be attributed to enhanced absorption in the visible light region due to the ultrathin NRs, more efficient charge separation/transportation owing to the formation of a p-n junction, and high exposure of reactive (001) facets resulting from the formation of a hierarchical structure. Moreover, this hierarchical photocatalyst shows high stability and excellent recycling properties.