Enhancement of Selective Fixation of Dinitrogen to Ammonia Under Modal Strong Coupling Conditions

Abstract

The production of ammonia from atmospheric nitrogen and water using sunlight is an important way to obtain ammonia as an energy carrier and is a new paradigm for achieving a low-carbon and sustainable-energy society. In this study, we attempted to enhance the ammonia photosynthesis efficiency both by increasing the electron supply using a novel photoanode composed of Au film, TiO2, and Au-NPs (ATA) with hybrid energy states due to modal strong coupling and by increasing the surface area of the Zr cathode. We investigated the key properties of this hybrid mode-assisted NH3 photosynthesis using two-electrode systems combining photoanodes and cathodes by performing photoelectrochemical measurements and product analysis. We found that the ATA structure has high absorptivity and enhances the quantum efficiency of ammonia photosynthesis and the surface area available to adsorb N-2 on the Zr cathode is a critical factor for enhancing the reaction rate.