Surface and interface engineering of hierarchical photocatalysts

In developing efficient heterogeneous photocatalysts, the design and fabrication of hierarchical semiconductors at the micro/nanometer scales have received much attention during the past decade due to their unique advantages in addressing the critical problems during photocatalysis. However, there are still many challenges in designing and constructing highly efficient hierarchical photocatalysts. Thus, in this review, we first systematically summarize and discusse the fundamentals and important interface engineering strategies of designing hierarchical photocatalysts, such as fabricating Z-Scheme heterojunctions, constructing Schottky-based heterojunctions, creating carbon-based heterojunctions and designing multicomponent heterojunctions. Then, especially, the different surface modification approaches of hierarchical porous photocatalysts, including loading cocatalysts, exposing the reactive facets, introducing defects/heteroatoms, adding photosensitizers, are highlighted. Finally, the major conclusions are made regarding this promising class of heterogeneous photocatalysts, and some perspectives are given on its future development. Through studying the important advances on this topic, it may pave a new avenue for fabricating highly effective hierarchical semiconductors for various applications in photocatalysis, electrocatalysis, thermal catalysis and other fields.