Challenges in temperature measurements in gas-phase photothermal catalysis

A reliable measurement of the sample temperature during photothermal catalysis experiments is of paramount importance in disentangling the thermal and non-thermal contributions to the overall process. Moreover, even small errors in the temperature value may lead to substantial mistakes in estimating the reaction rate due to the exponential dependence of the Arrhenius law. In this work, after general setup considerations, we discuss the challenges in reliably measuring the temperature of photocatalysts considering the case of thin-filmtitaniumnitride (TiN), anemergingplasmonic metal, and of titanium dioxide (TiO2), a benchmark semiconductor, under gas phase conditions. By evaluating the effects of the gas flux, gas composition, and choice of instrumentation, we show how all these parameters can significantly affect the values of the measured temperatures. This analysis highlights the critical points that researchers ought to consider when performing photothermal catalysis studies.