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Exceptional Catalytic Nature of Quantum Dots for Photocatalytic Hydrogen Evolution without External Cocatalysts
Author(s) -
Gao YuJi,
Li XuBing,
Wu HaoLin,
Meng ShuLin,
Fan XiangBing,
Huang MaoYong,
Guo Qing,
Tung ChenHo,
Wu LiZhu
Publication year - 2018
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201801769
Subject(s) - photocatalysis , quantum dot , materials science , catalysis , hydrogen production , nanotechnology , photochemistry , water splitting , exciton , hydrogen , chemical physics , chemical engineering , chemistry , physics , condensed matter physics , biochemistry , organic chemistry , engineering
The catalytic nature of semiconducting quantum dots (QDs) for photocatalytic hydrogen (H 2 ) evolution can be thoroughly aroused, not because of coupling with external cocatalysts, but through partially covering controlled amount of ZnS shell on the surface. Specifically, CdSe QDs, with an optimal coverage of ZnS (≈46%), can produce H 2 gas with a constant rate of ≈306.3 ± 21.1 µmol mg −1 h −1 during 40 h, thereby giving a turnover number of ≈(4.4 ± 0.3) × 10 5 , which is ≈110‐fold to that of unmodified CdSe QDs under identical conditions. The performance of H 2 evolution is comparable to or even better than the commonly used external cocatalysts, e.g., metal complexes, noble metals assisted photosystems. Mechanistic insights indicate that the dramatically enhanced activity and stability of bare QDs for photocatalytic H 2 production are derived from (i) inhibiting exciton annihilation at trap states, (ii) preventing the photo‐oxidation of core frameworks, and (iii) retaining tunneling efficiencies of photogenerated electrons and holes to reactive sites with partial ZnS coverage.