Photocatalytic N2 Fixation by Plasmonic Mo-Doped TiO2 Semiconductor

Photocatalytic N₂ fixation has attracted substantial attention in recent years, as it represents a green and sustainable development route toward efficiently converting N₂ to NH₃ for industrial applications. How to rationally design catalysts in this regard remains a challenge. Here we propose a strategy that uses plasmonic hot electrons in the highly doped TiO₂ to activate the inert N₂ molecules. The synthesized semiconductor catalyst Mo-doped TiO₂ shows a NH₃ production efficiency as high as 134 μmol·g^-1·h^-1 under ambient conditions, which is comparable to that achieved by the conventional plasmonic gold metal. By means of ultrafast spectroscopy we reveal that the plasmonic hot electrons in the system are responsible for the activation of N₂ molecules, enabling improvement the catalytic activity of TiO₂. This work opens a new avenue toward semiconductor plasmon-based photocatalytic N₂ fixation.