Mao Yueshuang, Wang Pengfei, Li Lina, Chen Zongwei, Wang Haitao, Li Yi, Zhan Sihui
MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, P. R. China.
School of Energy and Environmental Engineering, Hebei University of Technology, Tianjin, 300401, P. R. China.
Angew Chem Int Ed Engl. 2020 Feb 24;59(9):3685-3690. doi: 10.1002/anie.201914001. Epub 2020 Feb 6.
Defects in nanomaterials often lead to properties that are absent in their pristine counterparts. To date, most studies have focused on the effect of single defects, while ignoring the synergy of multiple defects. In this study, a model of photocatalytic O activation was selected to unravel the role of dual defects by decorating bismuth oxide with surface O vacancies and bulk O substitution simultaneously. The introduction of dual defects led to a spatial and electronic synergistic process: i) O substitution induced a local electric field in the bulk of BiO , which promoted bulk separation of electrons and holes immediately after their generation; ii) O vacancies efficiently lowered the conduction band, served as the capture center for electrons, and thus facilitated the adsorption and activation of O . This effect was greatly promoted by the coexistence of bulk O substitution, and DFT calculations showed that only O substitution near an O vacancy could have this effect.
纳米材料中的缺陷往往会导致其原始对应物所不具备的性质。迄今为止，大多数研究都集中在单一缺陷的影响上，而忽略了多种缺陷的协同作用。在本研究中，选择了一个光催化氧活化模型，通过同时用表面氧空位和体相氧取代修饰氧化铋来揭示双缺陷的作用。双缺陷的引入导致了一个空间和电子协同过程：i）氧取代在BiO体相中诱导了一个局部电场，在电子和空穴产生后立即促进了它们在体相中的分离；ii）氧空位有效地降低了导带，作为电子的捕获中心，从而促进了氧的吸附和活化。体相氧取代的共存极大地促进了这种效应，密度泛函理论计算表明，只有在氧空位附近的氧取代才能产生这种效应。
