Thermal effect in plasmon assisted photocatalyst: a parametric study

Recently, it has been suggested that chemical reactions can be facilitated by using mm-scale composites of metal nanoparticles on porous metal oxides when illuminated at their plasmonic resonance wavelength. This effect was shown recently to be predominantly associated with the heating induced by illumination [Dubi et al., Chem. Sci., 2020]. In this work, we study the parametric dependence of the temperature distribution in these composites numerically and provide analytic expressions for simple cases. It turns out that the physical picture emerging from the collective thermal response is quite different from the one that emerged from single particles. We show [Un & Sivan, Nanoscale, 2020] the temperature rise distribution in them is typically weakly-dependent on the illumination wavelength, pulse duration, particle shape, size, and density; but is strongly sensitive to the beam size and the host thermal conductivity. These results have a direct implication in the route for optimization of the reaction rates. On a more general level, this work would also be instrumental in uprooting some common misconceptions associated with the role of thermal effects in applications that rely on heat generation from a large number of particles.