Kiani Fatemeh, Bowman Alan R, Sabzehparvar Milad, Karaman Can O, Sundararaman Ravishankar, Tagliabue Giulia
Laboratory of Nanoscience for Energy Technologies (LNET), STI, École Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
Department of Materials Science & Engineering, Rensselaer Polytechnic Institute, 110 Eighth Street, Troy, New York 12180, United States.
ACS Energy Lett. 2023 Sep 19;8(10):4242-4250. doi: 10.1021/acsenergylett.3c01505. eCollection 2023 Oct 13.
Harnessing nonequilibrium hot carriers from plasmonic metal nanostructures constitutes a vibrant research field with the potential to control photochemical reactions, particularly for solar fuel generation. However, a comprehensive understanding of the interplay of plasmonic hot-carrier-driven processes in metal/semiconducting heterostructures has remained elusive. In this work, we reveal the complex interdependence among plasmon excitation, hot-carrier generation, transport, and interfacial collection in plasmonic photocatalytic devices, uniquely determining the charge injection efficiency at the solid/liquid interface. Measuring the internal quantum efficiency of ultrathin (14-33 nm) single-crystalline plasmonic gold (Au) nanoantenna arrays on titanium dioxide substrates, we find that the performance of the device is limited by hot hole collection at the metal/electrolyte interface. Our solid- and liquid-state experimental approach, combined with simulations, demonstrates more efficient collection of high-energy d-band holes traveling in the [111] orientation, enhancing oxidation reactions on {111} surfaces. These findings establish new guidelines for optimizing plasmonic photocatalytic systems and optoelectronic devices.
利用等离子体金属纳米结构中的非平衡热载流子构成了一个充满活力的研究领域，具有控制光化学反应的潜力，特别是用于太阳能燃料的产生。然而，对金属/半导体异质结构中等离子体热载流子驱动过程的相互作用的全面理解仍然难以捉摸。在这项工作中，我们揭示了等离子体光催化器件中等离子体激发、热载流子产生、传输和界面收集之间复杂的相互依存关系，独特地决定了固/液界面处的电荷注入效率。通过测量二氧化钛衬底上超薄（14 - 33纳米）单晶等离子体金（Au）纳米天线阵列的内量子效率，我们发现该器件的性能受金属/电解质界面处热空穴收集的限制。我们的固态和液态实验方法与模拟相结合，证明了在[111]取向传播的高能d带空穴能更有效地收集，增强了{111}表面上的氧化反应。这些发现为优化等离子体光催化系统和光电器件建立了新的指导原则。
