Selective synthesis of α-Bi2O3/rGO and β-Bi2O3/rGO heterostructures as efficient visible-light-driven photocatalysts

Heterostructures constructed by low-dimensional materials are promising for exploring novel properties. Herein, we demonstrate the selective synthesis of 1D/2D heterostructures of alpha-Bi2O3/rGO and beta-Bi2O3/rGO via different growth mechanisms through thermal evaporation. alpha-Bi2O3 nanowires were grown on the GO surface with the assistance of Au catalysts, while metastable tetragonal beta-Bi2O3 nanowires were stabilized on the GO surface. The nucleation of beta-Bi2O3 nanowires preferentially occurs on dangling bonds of C-O functional groups, which further reduces the interface defect density of the 1D/2D heterostructures. Both 1D/2D heterostructures showed enhanced visible-light-driven photocatalytic performance, which is attributable to efficient charge transfer between Bi2O3 nanowires and rGO, the relative low defect density of interface, and improved visible light absorption of rGO. The growth of 1D nanowires on 2D materials provides good contact with low interface defect density and facilitates more efficient photoinduced charge separation. These results provide an effective way to prepare various 1D/2D heterostructures with good interface properties for potential visible-light-driven photocatalytic applications.