1. Constructing surface synergistic effect in Cu-Cu2O hybrids and monolayer H1.4Ti1.65O4·H2O nanosheets for selective cinnamyl alcohol oxidation to cinnamaldehyde.
- Author
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Song, Yujie, Wang, Hao, Liu, Guangsheng, Wang, Huan, Li, Liuyi, Yu, Yan, and Wu, Ling
- Subjects
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LEWIS acids , *PHOTOCATALYSIS , *IRRADIATION , *CHARGE transfer , *HYDROGEN transfer reactions - Abstract
Graphical abstract The Lewis acid sites (Ti) in TNS would selectively adsorb OH in cinnamyl alcohol forming surface C O···Ti O coordination species. Under visible light irradiation, interface charge transfer occurs from C O to Ti O , resulting in the activation of cinnamyl alcohol and the charge enrichment in Ti atoms of TiO 6. The molecule O 2 would be adsorbed on the electron enriched Ti atoms and reduced to O 2 − for the oxidation of alcohol. Due to the hybrid electronic states of Cu-Cu 2 O, the interface electronic transfer kinetics are tuned to inhibit the intramolecular hydrogen transfer for dominating the selectivity towards cinnamaldehyde. The synergistic effect of surface coordination-activation-photocatalysis enables an efficient and green synthesis. Highlights • The coordination of hydroxyl in alcohol with surface Lewis acid sites of H 1.4 Ti 1.65 O 4 ·H 2 O nanosheets. • Directional interface charges transfer from alcohol to nanosheet occur via surface coordination species. • The hybrid electronic states of Cu-Cu 2 O tune interface charges transfer kinetics. • Synergistic surface coordination-activation-photocatalysis for precies synthesis. Abstract A multifunctional photocatalyst is constructed based on Cu-Cu 2 O hybrid and monolayer H 1.4 Ti 1.65 O 4 ·H 2 O nanosheets via an in situ photo-deposition process (Cu-Cu 2 O/TNS). The prepared sample enables the oxidation of cinnamyl alcohol to cinnamaldehyde with over 95% of selectivity under visible light irradiation using molecule O 2 as the oxidant. In situ FTIR spectra suggest that the Lewis acid sites in TNS would selectively adsorbed the hydroxyl of cinnamyl alcohol forming surface C O∙∙∙Ti O coordination species. UV-DRS spectra reveal that light adsorption of TNS can be extended to visible light region due to the interface charges transfer from C OH to Ti O via the surface coordination, resulting in the activation of OH in alcohol. In situ ESR further indicates that directional interface charge transfer induces the charge enrichment in Ti atoms of TiO 6 , facilitating O 2 adsorption. XAFS results reveal that the hybrid electronic states of Cu-Cu 2 O efficiently improve the interface electronic transfer kinetics to inhibit the intramolecular hydrogen transfer for dominating the selectivity towards cinnamaldehyde. This work highlights the synergistic effect of surface coordination-activation-photocatalysis for selective photosynthesis of fine chemicals. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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