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 ultra-fast 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.