Selective dealloying of metal nanoparticles results in rattle-type hollow carbon nanoshells enclosing platinum nanoparticles, which are able to perform size-selective catalysis. Selective functionalization of the outer graphene-like carbon surface prevents agglomeration and leads to well dispersible nanocatalysts in aqueous solutions. The synthesis starts with the production of nanoparticles with a cobalt-platinum-alloy core surrounded by graphene-like carbon reducing flame spray synthesis. After surface functionalization, simultaneous pore formation in the shell-wall and dissolution of the cobalt results in platinum encapsulated in hollow carbon nanospheres. Catalytic oxidation of differently sized sugars (glucose and maltoheptaose) reveales size-selective catalytic properties of these platinum nanorattles.
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http://dx.doi.org/10.1039/c7sc03785f | DOI Listing |
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January 2025
Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, School of Chemistry and Materials Science, Jiangsu Normal, University Xuzhou, Jiangsu, 221116, P. R. China.
Fabricating visible-light-responsive metal-organic frameworks (MOFs) with high stability and effective catalytic functionality remains a long-term pursuit yet a great challenge. Herein, a strategy of increasing ligand and cluster connectivity is developed to construct highly stable fluorescein MOFs, La-CFL, presenting a new (4,8)-connected topological structure compared to Cd-FL constructed using 6-connected dinuclear clusters and 3-connected tritopic ligands. La(CFL) containers like Chinese "Ritual Wine Vessels (Jue)" resemble linear arrangements interconnected by the [La(COO)] clusters.
View Article and Find Full Text PDFACS Omega
December 2024
Department of Chemistry, Southern Methodist University, Dallas, Texas 75275, United States.
The design and synthesis of photoactive metal-free 2D materials for selective heterogeneous photoredox catalysis continue to be challenging due to issues related to nonrecyclability, and limited photo- and chemical stability. Herein, we report the photocatalytic properties of a triazine-based porous COF, , which is found to be capable of facilitating both SET (single electron transfer) for photocatalytic reductive debromination of phenacyl bromide in absence of oxygen and generation of reactive oxygen species (ROS) for benzylamine photo-oxidation in the presence of oxygen, respectively, under visible light irradiation. Inspired by the latter results, we further systematically investigated different-sized benzylamine substrates in this single-component reaction and compared the results with an analogous COF () exhibiting a larger pore size.
View Article and Find Full Text PDFJACS Au
August 2024
Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560012, India.
Molecular hosts with functional cavities can emulate enzymatic behavior through selective encapsulation of substrates, resulting in high chemo-, regio-, and stereoselective product formation. It is still challenging to synthesize enzyme-mimicking hosts that exhibit a narrow substrate scope that relies upon the recognition of substrates based on the molecular size. Herein, we introduce a Pd self-assembled water-soluble molecular capsule [ ] () that was formed through the self-assembly of a ligand (4',4‴'-(1,4-phenylene)bis(1',4'-dihydro-[4,2':6',4″-terpyridine]-3',5'-dicarbonitrile)) with the acceptor -[(en)Pd(NO)] [en = ethane-1,2-diamine] ().
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2024
State Key Laboratory of Organic-Inorganic Composites, Key Lab of Biomedical Materials of Natural Macromolecules (Ministry of Education), Beijing Laboratory of Biomedical Materials, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
ACS Appl Mater Interfaces
August 2024
Zhejiang-Malaysia Joint Research Laboratory for Agricultural Product Processing and Nutrition, College of Food and Pharmaceutical Sciences, Ningbo University, Ningbo 315211, China.
The stimulus-responsive regulation of enzyme catalytic activity and selectivity provides a new opportunity to extend the functionality and efficiency of immobilized enzymes. This work aims to design and synthesize a thermo-switchable enzyme@MOF for size-selective biocatalysis and biosensing through the immobilization of lipase (CRL) within ZIF-8 functionalized with thermally responsive polymer, poly(-isopropylacrylamide) (PNIPAM) (CRL@ZIF-8-PNIPAM). Unlike free CRL, which does not demonstrate substrate selectivity, we can reversibly tune the pore size of the ZIF-8-PNIPAM nanostructures (open pores or blocked pores) through temperature stimulus and subsequently modulate the substrate selectivity of CRL@ZIF-8-PNIPAM.
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