Creation of an internal electric field in SnO2@ZnS-ZnSn(OH)6 dual-type-II heterojunctions for efficient NO photo-oxidation

Well-designed heterojunction photocatalysts are promising high-performance materials, effective in inducing charge transfer to achieve a particular migration path and long-lasting carriers. However, the traditional binary heterojunction photocatalysts still show low-efficiency charge separation. Her...

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Bibliographic Details
Published in:Science China materials 2023-04, Vol.66 (4), p.1447-1459
Main Authors: Chen, Bangfu, Ouyang, Ping, Li, Yuhan, Duan, Youyu, Lv, Kangle, Carabineiro, Sónia A. C., Dong, Fan
Format: Article
Language:English
Subjects:
Catalytic activity
Charge efficiency
Charge transfer
Chemistry and Materials Science
Chemistry/Food Science
Density functional theory
Electric fields
Heterojunctions
Heterostructures
Hydroxyl radicals
Materials Science
Oxidation
Photocatalysis
Photocatalysts
Reaction mechanisms
Tin dioxide
Valence band
Zinc sulfide
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Summary:Well-designed heterojunction photocatalysts are promising high-performance materials, effective in inducing charge transfer to achieve a particular migration path and long-lasting carriers. However, the traditional binary heterojunction photocatalysts still show low-efficiency charge separation. Herein, we report a direct dual-type-II SnO 2 @ZnS-ZHS (ZHS = ZnSn(OH) 6 ) ternary heterojunction, obtained by a facile in-situ face-to-face growth approach. Experimental results and density functional theory calculations reveal that the carrier dynamics of SnO 2 @ZnS-ZHS, with dual-type-II mechanisms, enables the photogenerated holes (h + ) of SnO 2 to migrate to the valence bands of ZHS and ZnS. This ensures that SnO 2 @ZnS-ZHS has twice as much oxidizing potential to produce enough hydroxyl radicals (·OH) to participate in NO oxidation reactions. With a unique dual-type-II ternary structure, SnO 2 @ZnS-ZHS shows the highest NO removal rate (44.5%) after 30 min, which is 23.5, 29.7 and 15.9 times higher than the values shown by the single components ZHS, SnO 2 and ZnS, respectively. A reaction mechanism is proposed. The improved photocatalytic activity shows the advantages of the SnO 2 @ZnS-ZHS heterostructure as a promising candidate for ternary heterojunction design.
ISSN:2095-8226
2199-4501
DOI:10.1007/s40843-022-2288-0