Nanojunction‐Mediated Photocatalytic Enhancement in Heterostructured CdS/ZnO,CdSe/ZnO,and CdTe/ZnO Nanocrystals |
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| Authors: | Clive Eley Dr. Tong Li Fenglin Liao Dr. Simon Michael Fairclough Dr. Jason M. Smith Prof. George Smith Prof. Shik Chi Edman Tsang |
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| Affiliation: | 1. Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford OX1 3QR (UK);2. Department of Material Science, University of Oxford, Oxford OX1 3PH (UK);3. Present address: Australian Center for Microscopy and Microanalysis, The University of Sydney, Sydney, NSW 2006, Australia) |
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| Abstract: | A series of highly efficient semiconductor nanocrystal (NC) photocatalysts have been synthesized by growing wurtzite‐ZnO tetrahedrons around pre‐formed CdS, CdSe, and CdTe quantum dots (QDs). The resulting contact between two small but high‐quality crystals creates novel CdX/ZnO heterostructured semiconductor nanocrystals (HSNCs) with extensive type‐II nanojunctions that exhibit more efficient photocatalytic decomposition of aqueous organic molecules under UV irradiation. Catalytic testing and characterization indicate that catalytic activity increases as a result of a combination of both the intrinsic chemistry of the chalcogenide anions and the heterojunction structure. Atomic probe tomography (APT) is employed for the first time to probe the spatial characteristics of the nanojunction between cadmium chalcogenide and ZnO crystalline phases, which reveals various degrees of ion exchange between the two crystals to relax large lattice mismatches. In the most extreme case, total encapsulation of CdTe by ZnO as a result of interfacial alloying is observed, with the expected advantage of facilitating hole transport for enhanced exciton separation during catalysis. |
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| Keywords: | atomic probe tomography cadmium nanocrystals photocatalysis semiconductors |
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