Installing coordinately unsaturated Fe-N-C structural units on polymer-composite-derived N-doped carbon offers highly active Fe-N sites for the electrochemical oxygen evolution reaction (OER) and reactive oxygen species (ROS) generation in tumor cells. An NHCl-driven high-temperature etching method was employed for the formation of FeSA950NC with coordinately unsaturated single Fe-atoms in an Fe-N(sp)-C structural unit together with N vacancies () and sp defects. The carbonization of Fe-phen@ZIF-8 at 800 °C for 30 min under argon, followed by grinding Fe-ZIF-8@RF-urea with NHCl at 950 °C for 2 hours, resulted in sp carbon defects and sites with coordination unsaturation in Fe-N due to NHCl decomposition to NH and HCl, which produced substantial internal stress for etching the carbon matrix. FeSA950NC was used to treat both A549 lung cancer cells and NIH3T3 mouse fibroblast cells to determine its potential as an efficient tumor therapeutic strategy using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and ROS assays. Additionally, FeSA950NC provided high stability and excellent OER activity through the Fe-N(sp)-C structural unit on pyridinic nitrogen by delivering at a minimum overpotential of 300 mV, which is much lower than that of structurally similar Fe-atom sites. The significantly stronger ROS and OER activities of FeSA950NC suggested the role of and sp-carbon defects with coordinately unsaturated Fe-N sites in improving its catalytic performance.
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http://dx.doi.org/10.1039/d4nr02553a | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Nankai University, School of Materials Science and Engineering, Smart Sensing Interdisciplinary Science Center, Collaborative Innovation Center of Chemical Science and Engineering, CHINA.
The practical applications of activation-unstable mesoporous metal-organic frameworks (MOFs) are often constrained by their structural instability. However, enhancing their stability could unlock valuable functionalities. Herein, we stabilized the otherwise unstable, post-activated structure of a novel mesoporous Zr(IV)-MOF, NKM-809, which uses a pyridine-containing amphiprotic linker (PPTB).
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, University of Wisconsin─Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States.
Hydrazides are known to catalyze reactions of α,β-unsaturated aldehydes via transient iminium formation. The iminium intermediate displays enhanced electrophilicity, which facilitates conjugate additions and cycloadditions. We observed that a hydrazide embedded in a seven-membered ring catalyzes homoaldol condensation of a simple aldehyde in a process that displays an approximate second-order dependence on the hydrazide.
View Article and Find Full Text PDFInorg Chem
January 2025
Hoffmann Institute of Advanced Materials, Shenzhen Polytechnic University, 7098 Liuxian Blvd, Nanshan District, Shenzhen 518055, P. R. China.
Metal-organic frameworks have received extensive development in the past three decades, which are generally constructed via the reaction between inorganic building units and commercially available or presynthesized organic linkers. However, the presynthesis of organic linkers is usually time-consuming and unsustainable due to multiple-step separation and purification. Therefore, methodology development of a new strategy is fundamentally important for the construction and further exploration of the applications of MOFs.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Center of Basic Molecular Science (CBMS), Department of Chemistry, Tsinghua University, Beijing, 100084, China.
Enantioselective hydrogenation of tetrasubstituted alkenes to form 1,2-contiguous stereocenters is a particularly appealing but highly challenging transformation in asymmetric catalysis. Despite the notable progress achieved in enantioselective hydrogenation over the past decades, enantioselective hydrogenation of all-carbon tetrasubstituted alkenes containing multiple alkyl groups remains an unsolved challenge. Here, we report a rhodium-catalyzed highly diastereo- and enantioselective hydrogenation of diverse acyclic multisubstituted alkenes under mild conditions.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Central South University, School of Physics and Electronics, 932 Lushan Nan Road, 410081, Changsha, CHINA.
Unsaturated Ni single atom catalysts (SACs), Ni-Nx (x=1,2,3), have been investigated to break the conventional Ni-N4 structural limitation and provide more unoccupied 3d orbitals for CO2RR intermediates adsorption, but their intrinsically low structural stability has seriously hindered their applications. Here, we developed a strategy by integrating Ni nanoclusters to stabilize unsaturated Ni-N3 atomic sites for efficient CO2 electroreduction to CO at industrial-level current. DFT calculations revealed that the incorporation of Ni nanocluster effectively stabilizes the unsaturated Ni-N3 atomic sites and modulates their electronic structure to enhance the adsorption of the key intermediate *COOH during CO2RR.
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