Xiyi Li, Qingqing Hou, Neng Liao, Jing Xiao*
Dye-sensitization has become a relatively mature technology for visible-light harvesting for the photocatalysts. However, it always suffers from desorption problem during the photocatalytic reaction which impedes it acts as a sustained and stable photocatalyst. Our work makes good use of the characteristic during the self-assembly process of metal-organic framework, synthetizing the RhB@NH2-UiO-66 to prevent the leaching of RhB without losing the crystalline lattice, as shown in Figure 1. The introduction of RhB significantly enhanced the light-absorption properties, which exhibits a large visible light absorption peak at around 553 nm, as shown in Figure 2. Therefore, in the visible-light-induced aerobic oxidation of benzyl alcohol, RhB@NH2-UiO-66 exhibits 3.5 times higher conversion than the pristine NH2-UiO-66 without losing the high selective, as shown in Figure 3. Moreover, the solution after the photocatalytic oxidation is measured by UV-Vis spectrophotometer to rule out the leaching of RhB. The mechanism of photocatalytic oxidation is analyzed by capture experiment and electron paramagnetic resonance, as shown in Figure 4. This work demonstrates the first example of the encapsulation of dye during the nucleation of metal-organic framework, which provides a facile and promising way to the consolidate dye-sensitized photocatalytic system.
Keywords: RhB@NH2-UiO-66; photosensitization; photocatalytic oxidation
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Figure 1 The XRD pattern of RhB@NH2-UiO-66 and NH2-UiO-66. |
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Figure 2 The UV-Vis spectra of RhB@NH2-UiO-66 and NH2-UiO-66. |
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Figure 3 Photocatalytic oxidation of benzyl alcohol in different system. Reaction condition: 15 mg photocatalyst, 3 ml solvent, 0.03 mmol benzyl alcohol, 1 atm O2, and 300 W Xenon lamp >420 nm |
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Figure 4 The mechanism of photocatalytic oxidation of benzyl alcohol over RhB@NH2-UiO-66 |
See more of this Group/Topical: Materials Engineering and Sciences Division