Speaker
Description
Light-driven chemistry at semiconductor surfaces couples photon absorption with thermal surface reactions in ways that are poorly understood at the molecular level. Using ultra-high vacuum (UHV) surface science techniques, we show how photocatalytic processes are composed of both thermal and photon-driven reaction steps, challenging the conventional “electrochemical” description of these systems.[1]
We present systematic studies of alcohol photocatalysis on well-defined TiO₂(110) single crystal surfaces, bare or decorated with metal clusters as co-catalyst. Alcohols can be converted into higher-value organic compounds and molecular H₂. Metal co-catalysts (Pt, Ni) do not merely act as electron sinks but actively participate in dark thermal chemistry, creating a synergistic mechanism where photogenerated carriers activate surface species and metal sites catalyze H₂ evolution. Furthermore, we quantitatively evaluate the mass spectrometric traces of the reactants, allowing us to quantify catalytic activity as well as reaction kinetics.[2][3]
Our results provide mechanistic understanding of heterogeneous photocatalysis, and extend the scope of chemical possibilities for selectively converting organic compounds. Key results can also be transferred to photocatalysis under ambient conditions.[4]