Visible Light Induced Selective Aerobic Formation of N ‐benzylidene Benzylamine over 2‐aminoterephthalic Acid Sensitized {110}‐Facetted BiOCl Nanosheets

Competitive photooxidation of small colorless organics controlled by oxygen vacancies under visible light

Visible-light photooxidation sensitized by surface attachment of small colorless organics on semiconductor photocatalysts has emerged as an economical method for photocatalytic synthesis or degradation. In particular, heteroatom (X = N and Cl)-containing substrates could undergo either C-N coupling or dechlorination degradation via sensitizing TiO2, but the mechanism in conducting the competitive visible-light sensitized photooxidations is still vague. Herein, the visible-light photooxidation of colorless 4-chlorobenzene-1,2-diamine (o-CAN) on TiO2 was revealed, contributing to selective C-N coupling rather than dechlorination. Oxygen vacancies (OVs) were in situ generated on the TiO2 surface, which could be dominant in weakening the Cl-Ti adsorption of o-CAN and regulating the activation of O2 for selective C-N coupling. The C-N coupling product, functionalized as the sensitizer, further promoted the visible-light photooxidation upon N-Ti and Cl-Ti coordination. This process was then confirmed by on-line mass spectrometric analysis, and the intermediates as well as their kinetics were determined. Thereby, theoretical calculations were employed to verify the roles of OVs in competitive photooxidation and lowering the energy barriers as well. Based on the comprehensive characterizations of both the catalysts and intermediates, this work has provided insights into competitive photooxidations under visible light.

Bioinspired Metalation of the Metal-Organic Framework MIL-125-NH2 for Photocatalytic NADH Regeneration and Gas-Liquid-Solid Three-Phase Enzymatic CO2 Reduction

Coenzyme NADH regeneration is crucial for sustained photoenzymatic catalysis of CO₂ reduction. However, light-driven NADH regeneration still suffers from the low regeneration efficiency and requires the use of a homogeneous Rh complex. Herein, a Rh complex-based electron transfer unit was chemically attached onto the linker of the MIL-125-NH₂ . The coupling between the light-harvesting iminopyridine unit and electron-transferring Rh-complex facilitated the photo-induced electron transfer for the NADH regeneration with the yield of 66.4 % in 60 mins for 5 cycles. The formate dehydrogenase was further deposited onto the hydrophobic layer of the membrane by a reverse filtering technique, which forms the gas-liquid-solid reaction interface around the enzyme site. It gave an enhanced formic acid yield of 9.5 mM in 24 hours coupled with the in situ regenerated NADH. The work could shed light on the construction of integrated inorganic-enzyme hybrid systems for artificial photosynthesis.

Periodically nanoporous hydrogen-bonded organic frameworks for high performance photocatalysis

The development of highly catalytic hydrogen-bonded organic frameworks (HOFs) is of great importance, but remains challenging. Herein, we demonstrate the fabrication of a periodically nanoporous HOF for high performance photocatalysis. Compared with the conventional microporous HOFs, the nanoporous HOF architecture has a larger number of free carboxyl groups on the surface and presents greatly improved photoelectrochemical properties. It exhibits high catalytic activity for the photo-oxidative coupling of amines under mild conditions such as air atmosphere and room temperature and without any co-catalysts, sacrificial reagents or photosensitizers. The relationship between the structure, properties and catalytic performance of the nanoporous HOF was studied by experimental and theoretical investigations. It shows that such a HOF structure facilitates reactant adsorption and O₂ dissociation, thus promoting the oxidative coupling reaction. This work provides a new way for improving the catalytic performance of a single HOF.

Recent developments on bismuth oxyhalide-based functional nanomaterials for biomedical applications

Multifunctional bismuth oxyhalide (BiOX, X = F, Cl, Br, and I) nanomaterials have great potential advantages in medical diagnostic and therapeutic applications. Pure BiOX nanomaterials have some limitations such as...

Does the intrinsic photocontrollable oxidase-mimicking activity of 2-aminoterephthalic acid dominate the activity of metal–organic frameworks?

The ligand ATA possesses intrinsic photocontrolled oxidase-like activity, showing promise in designing ATA-MOF with photoresponsive enzyme-like activity like Al-ATA and establishing the colorimetric strategy for Cu²⁺ detection.