Hot-Electron-Induced Photothermal Catalysis for Energy-Dependent Molecular Oxygen Activation

Hot electrons activate reactants and reduce the activation energy barrier (E_a ) of a reaction through electron donation. However, a comprehensive understanding of the intrinsic driving force of this electron-donating effect is lacking, let alone the precise manipulation of electron donation processes. Herein, the essential and promotional role of hot electron energy on the electron-donating effect was elucidated using molecular oxygen activation (MOA) as a model reaction. Through providing an available electron source to the conventional photo-thermal conversion system, the high energy carried by hot electrons was liberated and greatly enhanced the electron donation towards the LUMO (π*) orbit of O₂ . The energy was also transferred to O₂ and elevated the potential energy surface (PES) of MOA, which was reflected by the enhanced formation of superoxide oxygen anions. As predicted, the E_a of MOA decreased by 45.1 % and exhibited a substantial light dependence, demonstrating that MOA became energy-efficient due to improved exploitation and conversion of photon energies.