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Chemically Controllable Porous Polymer–Nanocrystal Composites with Hierarchical Arrangement Show Substrate Transport Selectivity
Functional organic–inorganic hybrid materials with tunable properties are useful across many application areas, ranging from gas storage to electronics, flame retardants, separations, and catalysis. Combining polymers, with a suite of functional groups and conformational flexibility, and inorganic nanoparticles, with tunable surface chemistry and composition, yields hybrids with novel functional properties. Specifically, in catalysis, control of the electronic environment at a metal interface is paramount in determining the catalytic properties. In this contribution, we describe a modular process to prepare porous polymer–nanocrystal (NC) composites in a hierarchical, multilayered synthesis, in which multiple parameters can be accurately tuned: polymer functional groups and the corresponding pore structure, the polymer layer thickness, and the NC size, shape, and composition. This process provides for a variety of controlled materials with high surface area, tunable chemistry, and thermal and chemical stabilities. Furthermore, we demonstrate their utility for shape- and size-selective catalytic conversions both in oxidation and hydrogenation reactions, where they show increased selectivity by orders of magnitude compared to conventional polymer-supported metal catalysts. In light of the high degree of control in the composite structure, this method allows for the design and realization of catalysts for several reactions and reaction environments and for nanomaterials with other applications.
Relaxed Substrate Requirements of Sterol 14[alpha]-Demethylase from Naegleria fowleri Are Accompanie
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Venglustat Inhibits Protein N-Terminal Methyltransferase 1 in a Substrate-Competitive Manner
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Solid-State High Harmonic Generation in Common Large Bandgap Substrate Materials
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Effect of TiO x Substrate Interactions on the Electrocatalytic Oxygen Reduction Reaction at Au Nanoparticles
Here, we report a robust model for studying electrocatalytic reactions at metal nanoparticles (NPs) in contact with metal oxide surfaces. The metal oxide layer (TiO x ) is prepared by atomic layer deposition, and it is sufficiently thin that it does not hinder electron transfer from the underlying conductive electrode to the supported AuNP electrocatalysts. In advance of the experiments, density functional theory (DFT) predicted that direct contact between AuNPs and TiO x would lead to enhanced activity for the oxygen reduction reaction (ORR). DFT attributes the observed ORR enhancement to partial charge transfer from oxygen vacancies within the TiO x film to the supported AuNPs and hence formation of anionic Au species. The experimental findings are in near quantitative agreement with the DFT results. Specifically, compared to isolated AuNPs, decreases of ~ 100 and ~ 50 mV in the ORR onset potential are observed experimentally for AuNPs supported on TiO 1.9 and TiO 2.0 films, respectively.
Quantification of Interactions at the Polymer–Substrate Interface: Implications for Nanoscale Behavior
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Substrate Channeling in Compartmentalized Nanoreactors
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Giant Periodic Pseudomagnetic Fields in Strained Kagome Magnet FeSn Epitaxial Films on SrTiO 3 (111) Substrate
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