Li Linjia, Jin Jing, Liu Junjun, Yang Jin, Song Wei, Yang Bai, Zhao Bing
State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P.R. China.
Nanoscale. 2021 Jan 14;13(2):1006-1015. doi: 10.1039/d0nr06293f. Epub 2020 Dec 24.
The excited carriers (electrons and holes) and heat energy that originate from plasmonic metal nanomaterials are crucial to the enhancement of the photocatalytic performance. In this study, an Ag@carbon dots (Ag@CDs) hybrid has been prepared with excellent Fenton-like photocatalytic and photothermal conversion properties for catalyzing HO to generate hydroxyl radicals (˙OH) for the degradation of crystal violet (CV) dye under full solar spectrum irradiation based on a unique plasmon effect. We have obtained some intrinsic kinetics information, including the reaction rate and apparent activation energy on the surface of the Ag@CDs, through a surface-enhanced Raman scattering strategy to investigate the contributions made by photocatalytic and photothermal effects in the plasmon mediated reaction under irradiation from ultraviolet (UV)/visible/near-infrared (NIR) light. In the visible light region, the Ag@CDs + HO system exhibits the fastest apparent reaction rate owing to the involvement of a large number of hot carriers, which are generated by the strongest plasmon effect, and the presence of the photothermal effect mediated by the plasmonic effect. As the wavelength of the illumination blue-shifts to the UV region, the plasmon effect is weakened, resulting in a decrease in the number of hot carriers. Furthermore, the hot carriers will not be further thermalized because of interband transitions. In addition, the catalytic performance of Ag@CDs in the NIR region is almost dominated by the photothermal effect. This work provides deep insights into understanding the plasmon-mediated photocatalytic mechanism of the Ag@CDs hybrid.
源自等离子体金属纳米材料的受激载流子（电子和空穴）及热能对于光催化性能的提升至关重要。在本研究中，基于独特的等离子体效应，制备了具有优异类芬顿光催化和光热转换性能的Ag@碳点（Ag@CDs）复合材料，用于在全太阳光谱照射下催化H₂O₂生成羟基自由基（˙OH）以降解结晶紫（CV）染料。我们通过表面增强拉曼散射策略获得了一些本征动力学信息，包括Ag@CDs表面的反应速率和表观活化能，以研究在紫外（UV）/可见/近红外（NIR）光照射下等离子体介导反应中光催化和光热效应的贡献。在可见光区域，Ag@CDs + H₂O₂体系表现出最快的表观反应速率，这归因于大量热载流子的参与，这些热载流子由最强的等离子体效应产生，以及等离子体效应介导的光热效应的存在。随着光照波长蓝移至紫外区域，等离子体效应减弱，导致热载流子数量减少。此外，由于带间跃迁，热载流子不会进一步热化。另外，Ag@CDs在近红外区域的催化性能几乎由光热效应主导。这项工作为理解Ag@CDs复合材料的等离子体介导光催化机理提供了深入见解。
