Enhancing the Supply of Activated Hydrogen to Promote Photocatalytic Nitrogen Fixation

Photocatalytic nitrogen fixation using water as a hydrogen source has proved a green avenue for ammonia synthesis, yet most ammonia yields reported to date are far from industrial demand. One of the bottlenecks lying in the surface catalytic process involves the acquisition and utilization of activated hydrogen (H*). Herein, a strategy regarding ameliorative H* supply for promoting photocatalytic N2 fixation was realized by utilizing the Pt-doped Ag nanoparticles supported on TiO2 (AgPt–TiO2). Irradiation of AgPt–TiO2 in N2-saturated water produced NH3 at a rate of 38.4 μmol g–1 h–1, which has a 7.7-fold increase compared with the value for pristine TiO2. The dramatically enhanced activity of AgPt–TiO2 results from the sufficient H* supply, thereby boosting significantly N2 hydrogenation and promoting ammonia formation. The promising strategy adopted here could be employed to regulate and acquire activated hydrogen of other efficient photocatalysts for N2 fixation and other photocatalytic reactions (e.g., CO2 conversion and hydrogen peroxide production).