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  1. Free, publicly-accessible full text available December 12, 2024
  2. Free, publicly-accessible full text available October 19, 2024
  3. Supported metal nanoparticle catalysts have become increasingly crucial for many catalytic applications. However, long‐term catalyst stability remains a problem due to catalyst deactivation caused by coke formation and sintering. The deposition of a thin overcoating via atomic layer deposition (ALD) onto metal‐supported nanoparticles has shown to greatly inhibit catalyst deactivation. This work utilizes a model catalyst system comprised of Pt nanoparticles supported on Al2O3to demonstrate the effect of an atomically thin overcoating on supported metal nanoparticles. Continuous operando small‐angle X‐ray scattering (SAXS) and X‐ray absorption near edge spectroscopy (XANES) monitor structural and electronic changes to the catalyst and overcoating during calcination. SAXS data fitting reveals the formation of nanopores in the overcoating at high temperatures, while XANES monitors the oxidation state of the Pt catalyst. Herein, the usefulness of combined X‐ray techniques is demonstrated to characterize supported metal catalysts to further understanding of the synergistic effects of the ALD overcoating to aid in the design of new catalyst materials.

     
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  4. Within the nuclear-electronic orbital (NEO) framework, the real-time NEO time-dependent density functional theory (RT-NEO-TDDFT) approach enables the simulation of coupled electronic-nuclear dynamics. In this approach, the electrons and quantum nuclei are propagated in time on the same footing. A relatively small time step is required to propagate the much faster electronic dynamics, thereby prohibiting the simulation of long-time nuclear quantum dynamics. Herein, the electronic Born–Oppenheimer (BO) approximation within the NEO framework is presented. In this approach, the electronic density is quenched to the ground state at each time step, and the real-time nuclear quantum dynamics is propagated on an instantaneous electronic ground state defined by both the classical nuclear geometry and the nonequilibrium quantum nuclear density. Because the electronic dynamics is no longer propagated, this approximation enables the use of an order-of-magnitude larger time step, thus greatly reducing the computational cost. Moreover, invoking the electronic BO approximation also fixes the unphysical asymmetric Rabi splitting observed in previous semiclassical RT-NEO-TDDFT simulations of vibrational polaritons even for small Rabi splitting, instead yielding a stable, symmetric Rabi splitting. For the intramolecular proton transfer in malonaldehyde, both RT-NEO-Ehrenfest dynamics and its BO counterpart can describe proton delocalization during the real-time nuclear quantum dynamics. Thus, the BO RT-NEO approach provides the foundation for a wide range of chemical and biological applications.

     
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  5. Free, publicly-accessible full text available March 14, 2025
  6. Free, publicly-accessible full text available May 16, 2024
  7. Abstract

    Large numbers of leaves fall on the earth each autumn. The current treatments of dead leaves mainly involve completely destroying the biocomponents, which causes considerable energy consumption and environmental issues. It remains a challenge to convert waste leaves into useful materials without breaking down their biocomponents. Here, we turn red maple dead leaves into an active three-component multifunctional material by exploiting the role of whewellite biomineral for binding lignin and cellulose. Owing to its intense optical absorption spanning the full solar spectrum and the heterogeneous architecture for effective charge separation, films of this material show high performance in solar water evaporation, photocatalytic hydrogen production, and photocatalytic degradation of antibiotics. Furthermore, it also acts as a bioplastic with high mechanical strength, high-temperature tolerance, and biodegradable features. These findings pave the way for the efficient utilization of waste biomass and innovations of advanced materials.

     
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