Parametric study of temperature distribution in plasmon-assisted photocatalysis

TL;DR

This paper analyzes how various parameters affect temperature distribution in plasmon-assisted photocatalysis, providing analytic expressions and insights to optimize experimental setups for improved heat generation and reaction rates.

Contribution

It offers a parametric analysis and analytic models for temperature distribution, showing weak dependence on many factors and linear dependence on beam radius and thermal conductivity.

Findings

Temperature distribution is weakly dependent on illumination spectrum, particle shape, size, and density.

Temperature distribution linearly depends on beam radius and host thermal conductivity.

Sensitivity of reaction rate varies with activation energy, aiding experimental optimization.

Abstract

Recently, there has been a growing interest in the usage of mm-scale composites of plasmonic nanoparticles for enhancing the rates of chemical reactions; the effect was shown recently to be predominantly associated with the elevated temperature caused by illumination. Here, we study the parametric dependence of the temperature distribution in these samples, and provide analytic expressions for simple cases. We show that since these systems are usually designed to absorb all the incoming light, the temperature distribution in them is weakly-dependent on the illumination spectrum, pulse duration, particle shape, size and density. Thus, changes in these parameters yield at most modest quantitative changes. We also show that the temperature distribution is linearly dependent on the beam radius and the thermal conductivity of the host. Finally, we study the sensitivity of the reaction rate to these parameters as a function of the activation energy and interpret various previous experimental reports. These results would simplify the optimization of photocatalysis experiments, as well as for other energy-related applications based on light harvesting for heat generation.