Plasmonic Silver-Nanoparticle-Catalysed Hydrogen Abstraction from the C(sp3 )-H Bond of the Benzylic Cα atom for Cleavage of Alkyl Aryl Ether Bonds

In-situ and wavelength-dependent photocatalytic strain evolution of a single Au nanoparticle on a TiO2 film

Photocatalysis is a promising technique due to its capacity to efficiently harvest solar energy and its potential to address the global energy crisis. However, the structure-activity relationships of photocatalyst during wavelength-dependent photocatalytic reactions remains largely unexplored because it is difficult to measure under operating conditions. Here we show the photocatalytic strain evolution of a single Au nanoparticle (AuNP) supported on a TiO2 film by combining three-dimensional (3D) Bragg coherent X-ray diffraction imaging with an external light source. The wavelength-dependent generation of reactive oxygen species (ROS) has significant effects on the structural deformation of the AuNP, leading to its strain evolution. Density functional theory (DFT) calculations are employed to rationalize the induced strain caused by the adsorption of ROS on the AuNP surface. These observations provide insights of how the photocatalytic activity impacts on the structural deformation of AuNP, contributing to the general understanding of the atomic-level catalytic adsorption process.

Hydrogen-transfer strategy in lignin refinery: Towards sustainable and versatile value-added biochemicals

Lignin, the most prevalent natural source of polyphenols on Earth, offers substantial possibilities for the conversion into aromatic compounds, which is critical for attaining sustainability and carbon neutrality. The hydrogen-transfer method has garnered significant interest owing to its environmental compatibility and economic viability. The efficacy of this approach is contingent upon the careful selection of catalytic and hydrogen-donating systems that decisively affect the yield and selectivity of the monomeric products resulting from lignin degradation. This paper highlights the hydrogen-transfer technique in lignin refinery, with a specific focus on the influence of hydrogen donors on the depolymerization pathways of lignin. It delineates the correlation between the structure and activity of catalytic hydrogen-transfer arrangements and the gamut of lignin-derived biochemicals, utilizing data from lignin model compounds, separated lignin, and lignocellulosic biomass. Additionally, the paper delves into the advantages and future directions of employing the hydrogen-transfer approach for lignin conversion. In essence, this concept investigation illuminates the efficacy of the hydrogen-transfer paradigm in lignin valorization, offering key insights and strategic directives to maximize lignin's value sustainably.

Single Atom-Dispersed Silver Incorporated in ZIF-8-Derived Porous Carbon for Enhanced Photothermal Activity and Antibacterial Activities

Purpose

Recently, Single-atom-loaded carbon-based material is a new environmentally friendly and stable photothermal antibacterial nanomaterial. It is still a great challenge to achieve single-atom loading on carbon materials.

Materials and Methods

Herein, We doped single-atom Ag into ZIF-8-derived porous carbon to obtain Ag-doped ZIF-8-derived porous carbon(AgSA-ZDPC). The as-prepared samples were characterized by XRD, XPS, FESEM, EDX, TEM, and HAADF-STEM which confirmed that the single-atom Ag successfully doped into the porous carbon. Further, the photothermal properties and antimicrobial activity of AgSA-ZDPC have been tested.

Results

The results showed that the temperature increased by 30 °C after near-infrared light irradiation(1 W/cm2) for 5 min which was better than ZIF-8-derived porous carbon(ZDPC). It also exhibits excellent photothermal stability after the laser was switched on and off 5 times. When the AgSA-ZDPC concentration was greater than 50 µg/mL and the near-infrared irradiation was performed for 5 min, the growth inhibition of S. aureus and E. coli was almost 100%.

Conclusion

This work provides a simple method for the preparation of single-atom Ag-doped microporous carbon which has potential antibacterial application.

Deconstructive annulation mediated one-pot synthesis of xanthene derivatives

Direct conversion of naphthoxazines to diverse xanthene derivatives was achieved under one-pot operation through deconstructive annulation methodology. Sequential oxidative C(sp3)-O/C(sp3)-N cleavage followed by intramolecular/intermolecular annulation reaction was carried out under aerobic reaction conditions. Mechanistic analyses performed on the substrate revealed that the C(sp3)-O bond cleavage supersedes the C(sp3)-N bond scission. The in situ generated Betti base intermediate through the C(sp3)-O cleavage was successfully isolated. Based on a molecular docking investigation, the intermolecular annulated products demonstrated good α-glucosidase inhibitory properties.

Probing local charge transfer processes of Pt-Au heterodimers in plasmon-enhanced electrochemistry by CO stripping techniques

CO-stripping experiments are employed as a highly structure-sensitive and in situ strategy to explore the mechanisms of plasmon-enhanced electrooxidation reactions. By using Pt-Au heterodimers as a model catalyst, the plasmon-induced current and potential changes on Pt and Au sites can be identified and explained.

Active Site Engineering on Plasmonic Nanostructures for Efficient Photocatalysis

Plasmonic nanostructures have shown immense potential in photocatalysis because of their distinct photochemical properties associated with tunable photoresponses and strong light-matter interactions. The introduction of highly active sites is essential to fully exploit the potential of plasmonic nanostructures in photocatalysis, considering the inferior intrinsic activities of typical plasmonic metals. This review focuses on active site-engineered plasmonic nanostructures with enhanced photocatalytic performance, wherein the active sites are classified into four types (i.e., metallic sites, defect sites, ligand-grafted sites, and interface sites). The synergy between active sites and plasmonic nanostructures in photocatalysis is discussed in detail after briefly introducing the material synthesis and characterization methods. Active sites can promote the coupling of solar energy harvested by plasmonic metal to catalytic reactions in the form of local electromagnetic fields, hot carriers, and photothermal heating. Moreover, efficient energy coupling potentially regulates the reaction pathway by facilitating the excited state formation of reactants, changing the status of active sites, and creating additional active sites using photoexcited plasmonic metals. Afterward, the application of active site-engineered plasmonic nanostructures in emerging photocatalytic reactions is summarized. Finally, a summary and perspective of the existing challenges and future opportunities are presented. This review aims to deliver some insights into plasmonic photocatalysis from the perspective of active sites, expediting the discovery of high-performance plasmonic photocatalysts.