Metal-organic frameworks (MOFs) offer versatile templates/precursors to prepare supported metal catalysts. However, the afforded catalysts usually exhibit microporous structures and unsuitable wettability, which will restrict the accessibility of active sites in liquid-phase reactions. Herein, an etching-functionalization strategy is developed for the construction of a tannic-acid-functionalized MOF with a unique hollow-wall and 3D-ordered macroporous (H-3DOM) structure. The functional MOF can be further employed as an ideal precursor for the synthesis of cobalt supported on oxygen/nitrogen-co-doped carbon composites with H-3DOM structures, and hydrophilic surface. The H-3DOM structure can improve the external surface area to maximize the exposure of active sites. Moreover, the oxygen-containing functional groups can enhance the surface wettability to guarantee the external active sites to be more electrochemically accessible in aqueous electrolyte. Benefitting from these outstanding characteristics, H-3DOM-Co/ONC exhibits high electrocatalytic activity in the oxygen reduction reaction, superior to its counterparts without the hierarchically ordered structure and surface functionalization.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/adma.202301894 | DOI Listing |
Proc Natl Acad Sci U S A
January 2025
California Institute for Quantitative Biosciences, University of California, Berkeley, CA 94720.
Polysaccharide monooxygenase (PMO) catalysis involves the chemically difficult hydroxylation of unactivated C-H bonds in carbohydrates. The reaction requires reducing equivalents and will utilize either oxygen or hydrogen peroxide as a cosubstrate. Two key mechanistic questions are addressed here: 1) How does the enzyme regulate the timely and tightly controlled electron delivery to the mononuclear copper active site, especially when bound substrate occludes the active site? and 2) How does this electron delivery differ when utilizing oxygen or hydrogen peroxide as a cosubstrate? Using a computational approach, potential paths of electron transfer (ET) to the active site copper ion were identified in a representative AA9 family PMO from (PMO9E).
View Article and Find Full Text PDFInorg Chem
January 2025
School of Chemistry and Chemical Engineering, and Institute for Innovative Materials and Energy, Yangzhou University, 180 Si-Wang-Ting Road, Yangzhou 225002, China.
The interaction between electrocatalytic active centers and their support is essential to the electrocatalytic performance, which could regulate the electronic structure of the metal centers but requires precise design. Herein, we report on covalent grafting of graphene quantum dots (GQDs) on stepped TiO as a support to anchoring cobalt phosphide nanoparticles (CoP/GQD/S-TiO) for electrocatalytic hydrogen evolution reaction (HER). The covalent ester bonds between GQDs and TiO endow enlarged anchoring sites to achieve highly dispersed electroactive CoP nanoparticles but, more importantly, provide an efficient electron-transfer pathway from TiO to GQDs which could regulate the electronic structure of CoP.
View Article and Find Full Text PDFChem Biol Drug Des
January 2025
Department of Molecular Biology and Biochemistry, University of California, Irvine, California, USA.
A new series of 13 ritonavir-like inhibitors of human drug-metabolizing CYP3A4 was rationally designed to study the R side-group and R end-group interplay when the R side-group is represented by phenyl. Spectral, functional, and structural characterization showed no improvement in the binding affinity and inhibitory potency of R/R-phenyl inhibitors upon elongation and/or fluorination of R-Boc (tert-butyloxycarbonyl) or its replacement with benzenesulfonyl. When R is pyridine, the impact of R-phenyl-to-indole/naphthalene substitution was multidirectional and highly dependent on side-group stereo configuration.
View Article and Find Full Text PDFACS Nano
January 2025
Department of Chemistry and Biochemistry, Queens College, Flushing, New York 11367, United States.
Semiconductor nanomaterials and nanostructured interfaces have important technological applications, ranging from fuel production to electrosynthesis. Their photocatalytic activity is known to be highly heterogeneous, both in an ensemble of nanomaterials and within a single entity. Photoelectrochemical imaging techniques are potentially useful for high-resolution mapping of photo(electro)catalytic active sites; however, the nanoscale spatial resolution required for such experiments has not yet been attained.
View Article and Find Full Text PDFAdv Skin Wound Care
January 2025
Abigail C. Judge, BS, is Medical Student, School of Medicine, Yale University, New Haven, Connecticut, United States. Amir H. Tahernia, MD, is Surgeon, Olympia Medical Center and Cedars-Sinai Medical Center, Los Angeles, California.
Background: Hidradenitis suppurativa is a chronic, inflammatory disease involving the pilosebaceous unit of apocrine gland-bearing skin. Wide surgical excision, wherein margins extend beyond active lesions, is considered curative.
Objective: To evaluate the safety and efficacy of wide surgical excision in the treatment of hidradenitis suppurativa.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!