Plasmonic MoO 3− x /Ag Photocatalyst for the Fixation of N 2 from Air with the Solar Energy Conversion Efficiency Reaching over 0.28%

Abstract Storing solar energy in chemical bonds through photocatalysis under ambient conditions is of great importance for sustainable development and carbon neutrality. In addition to the design of new photocatalysts with high activities, efficient solar energy delivery and the acceleration of reactant mass transfer kinetics are also crucial for efficient energy conversion. Herein, a new type of plasmonic Schottky‐barrier‐free MoO 3− x /Ag photocatalyst is designed for efficient NH 3 production. The photocatalyst exhibits strong light absorption and utilization under sunlight illumination. The construction of a bilayer system reduces the light attenuation by water in the near‐infrared region and accelerates the N 2 mass transfer kinetics. As a result, the photocatalytic activity is largely boosted. A high solar‐to‐chemical energy conversion efficiency of over 0.28% (±0.01%) is reached with air directly used as the feeding gas. The study offers a promising pathway for the rational design of photocatalysts and photocatalytic platforms, enabling greatly enhanced solar‐to‐chemical energy conversion.