The structure of UiO-66(Ce) is formed by CeO defective nanoclusters connected by terephthalate ligands. The initial presence of accessible Ce sites in the as-synthesized UiO-66(Ce) has been determined by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR)-CO analyses. Moreover, linear scan voltammetric measurements reveal a reversible Ce/Ce interconversion within the UiO-66(Ce) material, while nanocrystalline ceria shows an irreversible voltammetric response. This suggests that terephthalic acid ligands facilitate charge transfer between subnanometric metallic nodes, explaining the higher oxidase-like activity of UiO-66(Ce) compared to nanoceria for the mild oxidation of organic dyes under aerobic conditions. Based on these results, we propose the use of Ce-based metal-organic frameworks (MOFs) as efficient catalysts for the halogenation of activated arenes, as 1,3,5-trimethoxybenzene (TMB), using oxygen as a green oxidant. Kinetic studies demonstrate that UiO-66(Ce) is at least three times more active than nanoceria under the same reaction conditions. In addition, the UiO-66(Ce) catalyst shows an excellent stability and can be reused after proper washing treatments. Finally, a general mechanism for the oxidative halogenation reaction is proposed when using Ce-MOF as a catalyst, which mimics the mechanistic pathway described for metalloenzymes. The superb control in the generation of subnanometric CeO defective clusters connected by adequate organic ligands in MOFs offers exciting opportunities in the design of Ce-based redox catalysts.
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http://dx.doi.org/10.1021/acsami.1c07496 | DOI Listing |
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January 2025
State Key Laboratory of Advanced Special Steel & Shanghai Key Laboratory of Advanced Ferrometallurgy, School of Materials Science and Engineering, Shanghai University, Shanghai, 200444, China.
Interface engineering for electrocatalysts has proven to be an effective method for modulating electrocatalytic properties, yet a more efficient and straightforward strategy to construct a valid heterointerface for further enhancing interface effects is urgently needed for boosting oxygen evolution reactions (OER) at large current. Herein, a closely compacted heterostructure combining NiCo-metal-organic framework (MOF) and Ce-MOF is in situ formed through a one-step hydrothermal treatment, and partial phosphorization is employed to further enhance the interface effect between the newly formed urchin-shaped NiCoP shells and hexagonal rod-like Ce-MOF cores on nickel foam (NiCoP/Ce-MOF@NF). Experimental and theoretical results indicate that the heterogeneous NiCoP/Ce-MOF@NF, characterized by a more intensive interface rather than a simple physical mixture, generates an OER-beneficial electronic structure, significantly facilitates charge transfer and reaction kinetics, and creates a synergistically stable structure.
View Article and Find Full Text PDFEnviron Res
January 2025
Chemistry Department, College of Science, Jouf University, P.O. Box 2014, Sakaka, Saudi Arabia. Electronic address:
This study presents the development and optimization of Ce-MOF-808 nanocrystals supported by metallic and bimetallic nanoparticles (Au, Ag, and Pd) for the efficient reduction of nitrophenol. Using a sol-immobilization method, we synthesized a series of catalysts, including Au/Ce-MOF-808, Au-Ag/Ce-MOF-808, and Au-Pd/Ce-MOF-808, and evaluated their catalytic efficacy of 4-nitrophenol (4-NP) reduction using NaBH₄ under mild conditions. Initially, effects of time (1-18 min), and catalyst dose (1-6 mg) on the reduction of nitrophenol were investigated through the one-factor-at-a-time experiment.
View Article and Find Full Text PDFNanomaterials (Basel)
August 2024
Shandong Provincial Key Laboratory of Molecular Engineering, School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.
Photocatalysis is the most promising green approach to solve antibiotic pollution in water, but the actual treatment effect is limited by photocatalytic activity. Herein, Bi and BiOCl were loaded onto the surface of Ce-MOF (metal-organic framework) using an electrostatic adsorption method, and a special ternary heterojunction of Ce/Bi/BiOCl was successfully prepared as a photocatalyst for the degradation of tetracycline (TC). FTIR demonstrated that the obtained photocatalyst contains functional groups such as -COOH belonging to Ce-MOF and characteristic crystal planes of Bi and BiOCl, indicating the successful construction of a ternary photocatalyst.
View Article and Find Full Text PDFBiomaterials
January 2025
School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore. Electronic address:
Copper-catalyzed click chemistry offers creative strategies for activation of therapeutics without disrupting biological processes. Despite tremendous efforts, current copper catalysts face fundamental challenges in achieving high efficiency, atom economy, and tissue-specific selectivity. Herein, we develop a facile "mix-and-match synthetic strategy" to fabricate a biomimetic single-site copper-bipyridine-based cerium metal-organic framework (Cu/Ce-MOF@M) for efficient and tumor cell-specific bioorthogonal catalysis.
View Article and Find Full Text PDFSci Rep
July 2024
Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan.
Wastewater treatment is inevitably required to alleviate the pollution of water resources by various contaminants such as antibiotics. MOFs are novel materials with photocatalytic activities. In this study, sonophotocatalytic degradation of tetracycline (TC) by the Cerium-based MOF (Ce-MOF) is optimized by modification of its synthesis route.
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