Enhanced Photocatalytic Activity of Bismuth Precursor by Rapid Phase and Surface Transformation Using Structure-Guided Combustion Waves

The development of an efficient method for manipulating phase and surface transformations would facilitate the improvement of catalytic materials for use in a diverse range of applications. Herein, we present the first instance of a submicrosecond time frame direct phase and surface transformation of Bi(NO₃)₃ rods to nanoporous β-Bi₂O₃ rods via structure-guided combustion waves. Hybrid composites of the prepared Bi(NO₃)₃·H₂O rods and organic fuel were fabricated by a facile preparation method. The anisotropic propagation of combustion waves along the interfacial boundaries of Bi(NO₃)₃·H₂O rods induced direct phase transformation to β-Bi₂O₃ rods in the original structure due to the rapid pyrolysis, while the release of gas molecules enabled the formation of nanoporous structures on the surfaces of rods. The developed β-Bi₂O₃ rods showed improved photocatalytic activity for the photodegradation of rhodamine B in comparison with Bi(NO₃)₃·H₂O rods and α-Bi₂O₃ rods due to the more suitable interdistance and the large contact areas of the porous surfaces. This new method of using structure-guided combustion waves for phase and surface transformation may contribute to the development of new catalysts as well as the precise manipulation of diverse micronanostructured materials.