Deng Yuting, Zhou Hongpeng, Zhao Yue, Yang Bin, Shi Ming, Tao Xiaoping, Yang Songqiu, Li Rengui, Li Can
State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian, 116023, P. R. China.
University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Small. 2022 Feb;18(5):e2103245. doi: 10.1002/smll.202103245. Epub 2021 Nov 11.
Crystal facet engineering has been recognized as a powerful strategy to finely modulate the charge separation behavior in semiconductor photocatalysis; however, disclosing the intrinsic roles that the morphologies and crystal facets play on photogenerated charge separation of semiconductor nanocrystals remains elusive. Herein, exemplified on the typical visible-light-responsive photocatalyst bismuth vanadate (BiVO ), for the first time, the successful fabrication is reported of well-defined BiVO square nanocrystals with precisely controllable (040)/(200) facet proportion, which undergo a dissolution-recrystallization-facet growth process accompanied with tetragonal to monoclinic phase transition. Spatial separation of photogenerated electrons and holes has been evidently demonstrated to take place between (040) and (200) facets of BiVO nanocrystals, on which the charge separation efficiency is verified to definitely depend on the facet proportion of (040)/(200). Further theoretical simulation reveals that the matching degree of charge collection length and crystal configuration is considered to be the major factor determining charge separation efficiency of BiVO nanocrystals. This study presents a strategy to fabricate morphology-tailored semiconductors, which will be favorable to advance the understanding of spatial charge separation in semiconductor photocatalysis.
晶面工程已被认为是一种在半导体光催化中精细调节电荷分离行为的有效策略；然而，揭示形貌和晶面对半导体纳米晶体光生电荷分离所起的内在作用仍然难以捉摸。在此，以典型的可见光响应光催化剂钒酸铋（BiVO₄）为例，首次报道了成功制备出具有精确可控的（040）/（200）面比例的形貌明确的BiVO₄方形纳米晶体，其经历了溶解 - 再结晶 - 晶面生长过程，并伴随着四方相向单斜相的转变。已明显证明光生电子和空穴在BiVO₄纳米晶体的（040）和（200）面之间发生空间分离，电荷分离效率被证实确实取决于（040）/（200）的面比例。进一步的理论模拟表明，电荷收集长度与晶体构型的匹配程度被认为是决定BiVO₄纳米晶体电荷分离效率的主要因素。本研究提出了一种制备形貌定制半导体的策略，这将有利于推进对半导体光催化中空间电荷分离的理解。
