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arXiv · 1902.03169

Thermal effects - an alternative mechanism for plasmonic-assisted photo-catalysis

Yonatan Sivan·Ieng Wai Un·Yonatan Dubi
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Abstract

Recent experiments claimed that the enhancement of catalytic reaction rates occurs via the reduction of activation barriers driven by non-equilibrium (``hot'') electrons in plasmonic metal nanoparticles. These experiments place plasmonic photo-catalysis as a promising path for enhancing the efficiency of various chemical reactions. Here, we argue that what appears to be photo-catalysis is in fact thermo-catalysis, driven by the well-known plasmon-enhanced ability of illuminated metallic nanoparticles to serve as heat sources. Specifically, we point to some of the most important papers in the field, and show that a simple theory of illumination-induced heating can explain the extracted experimental data to remarkable agreement, with minimal to no fit parameters. We further show that any small temperature difference between the photocatalysis experiment and a control experiment performed under uniform external heating is effectively amplified by the exponential sensitivity of the reaction, and very likely to be interpreted incorrectly as ``hot'' electron effects.

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Yonatan Sivan, Ieng Wai Un, Yonatan Dubi. 2019-02-08. Thermal effects - an alternative mechanism for plasmonic-assisted photo-catalysis. https://arxiv.org/abs/1902.03169

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