Challenges and prospects of plasmonic metasurfaces for photothermal catalysis
Challenges and prospects of plasmonic metasurfaces for photothermal catalysis
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DOI：
10.1515/nanoph-2022-0073
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发表时间：
2022-05-23
期刊：
影响因子：
7.5
通讯作者：
Naldoni, Alberto
中科院分区：
文献类型：
--
作者：
Mascaretti, Luca;Schirato, Andrea;Naldoni, Alberto
利用热化学转化化学品的太阳能热技术需要极高的光密度。利用等离子体纳米结构可以通过宽带光吸收提供更有效的太阳能到热转换来显著提高反应速率。此外，热载流子和局部场增强效应可以改变反应途径。这些发现推动了光热催化领域的发展，该领域旨在利用太阳能照明而不是传统热源来驱动工业相关的化学反应。然而，只有在衬底上的等离子体纳米单元的大阵列，即，等离子体超颖表面允许在有限厚度（数百纳米）内的准单一和宽带太阳光吸收，以用于实际应用。通过适度的光浓度（类似于10个太阳），超颖表面达到与常规热化学反应器相同的温度，或者等离子体纳米颗粒床反应器在类似于100个太阳下达到相同的温度。等离子体超颖表面，然而，已被大多忽视，迄今为止在光热催化领域的应用。在这个角度来看，我们讨论的潜力等离子体超颖表面在这一新兴领域的研究。我们目前的数值模拟和实验案例研究，说明如何宽带吸收可以在有限的厚度内实现这些纳米结构材料。该方法突出了与等离子体单元的有序阵列相关的不同增强效应之间的协同作用，以及比较厚的结构（例如粉末状催化剂）更快的动力学的有效传热。我们预见，等离子体超颖表面可以在开发用于将化学原料转化为燃料的模块化结构中发挥重要作用，而不需要极端的光浓度。定制的基于超表面的系统可以导致小规模和低成本的分散式反应堆，而不是大规模的基础设施密集型发电厂。
Solar-thermal technologies for converting chemicals using thermochemistry require extreme light concentration. Exploiting plasmonic nanostructures can dramatically increase the reaction rates by providing more efficient solar-to-heat conversion by broadband light absorption. Moreover, hot-carrier and local field enhancement effects can alter the reaction pathways. Such discoveries have boosted the field of photothermal catalysis, which aims at driving industrially-relevant chemical reactions using solar illumination rather than conventional heat sources. Nevertheless, only large arrays of plasmonic nano-units on a substrate, i.e., plasmonic metasurfaces, allow a quasi-unitary and broadband solar light absorption within a limited thickness (hundreds of nanometers) for practical applications. Through moderate light concentration (similar to 10 Suns), metasurfaces reach the same temperatures as conventional thermochemical reactors, or plasmonic nanoparticle bed reactors reach under similar to 100 Suns. Plasmonic metasurfaces, however, have been mostly neglected so far for applications in the field of photothermal catalysis. In this Perspective, we discuss the potentialities of plasmonic metasurfaces in this emerging area of research. We present numerical simulations and experimental case studies illustrating how broadband absorption can be achieved within a limited thickness of these nanostructured materials. The approach highlights the synergy among different enhancement effects related to the ordered array of plasmonic units and the efficient heat transfer promoting faster dynamics than thicker structures (such as powdered catalysts). We foresee that plasmonic metasurfaces can play an important role in developing modular-like structures for the conversion of chemical feedstock into fuels without requiring extreme light concentrations. Customized metasurface-based systems could lead to small-scale and low-cost decentralized reactors instead of large-scale, infrastructure-intensive power plants.