Lyu Pin, Espinoza Randy, Nguyen Son C
Department of Chemistry and Biochemistry, University of California, Merced, 5200 North Lake Road, Merced, California 95343, United States.
J Phys Chem C Nanomater Interfaces. 2023 Aug 4;127(32):15685-15698. doi: 10.1021/acs.jpcc.3c04436. eCollection 2023 Aug 17.
Photocatalysis induced by localized surface plasmon resonance of metallic nanoparticles has been studied for more than a decade, but photocatalysis originating from direct interband excitations is still under-explored. The spectral overlap and the coupling of these two optical regimes also complicate the determination of hot carriers' energy states and eventually hinder the accurate assignment of their catalytic role in studied reactions. In this Featured Article, after reviewing previous studies, we suggest classifying the photoexcitation via intra- and interband transitions where the physical states of hot carriers are well-defined. Intraband transitions are featured by creating hot electrons above the Fermi level and suitable for reductive catalytic pathways, whereas interband transitions are featured by generating hot d-band holes below the Fermi level and better for oxidative catalytic pathways. Since the contribution of intra- and interband transitions are different in the spectral regions of localized surface plasmon resonance and direct interband excitations, the wavelength dependence of the photocatalytic activities is very helpful in assigning which transitions and carriers contribute to the observed catalysis.
金属纳米颗粒的局域表面等离子体共振诱导的光催化已经研究了十多年，但源于直接带间激发的光催化仍未得到充分探索。这两种光学机制的光谱重叠和耦合也使热载流子能态的确定变得复杂，最终阻碍了对其在研究反应中催化作用的准确归属。在这篇专题文章中，在回顾了以往的研究之后，我们建议通过带内和带间跃迁对光激发进行分类，其中热载流子的物理状态是明确的。带内跃迁的特点是在费米能级之上产生热电子，适用于还原催化途径，而带间跃迁的特点是在费米能级之下产生热d带空穴，更适合氧化催化途径。由于带内和带间跃迁在局域表面等离子体共振和直接带间激发的光谱区域中的贡献不同，光催化活性的波长依赖性对于确定哪些跃迁和载流子对观察到的催化作用有贡献非常有帮助。
