Self-templated Constructing of Heterophase Junction into Hierarchical Porous Structure of Semiconductors for Promoting Photogenerated Charge Separation

It is well-known that photogenerated charge separation is the key and bottleneck step to determine the solar energy efficiency in photocatalysis. Although strategies for facilitating spatial charge separation of semiconductor-based photocatalysts like heterojunctions, especially for heterophase junctions have been recognized as useful and adequate approaches, the original morphology-tailored structures are always challenging to be maintained during the thermal-induced phase transformation process. Herein, using a facile self-templated method, we successfully fabricate heterophase junction into the well-defined hierarchical porous structure of visible-light-responsive semiconductor, bismuth oxide (Bi2O3), without destroying the its unique hierarchical porous morphology. Such organic integration of heterophase junction and hierarchical porous structure are demonstrated to enable highly efficient separation of photogenerated electrons and holes, resulting in a remarkable enhancement in photocatalytic activities. Our work showcases a general concept for developing artificial photocatalyst systems via integrating efficient charge separation path into the unique morphology-tailoring of semiconductors for highly efficient solar energy conversion.