Plasmon-assisting surface reaction on gas–vapor-solid photothermal catalytic system for efficient ammonia photosynthesis

Abstract

Photosynthetic nitrogen reduction reaction (photo-NRR) is an eco-friendly and promising alternative route to energy-intensive Haber-Bosch process, but this emerging technology is limited in practical applications originating from the unsatisfactory N₂-to-NH₃ conversion efficiencies hindered by inefficient photocatalysts and intrinsic deficiencies in conventional gas–liquid-solid system. Herein, an innovative photothermal catalytic system, composed of porous g-C₃N₄/Fe-dispersed MXene aerogel and gas–vapor-solid catalytic environment, is pioneered to revolutionarily conquer the weak photoelectronic/photothermal response, water-induced light attenuation and low aqueous solubility/diffusibility of N₂ in traditional NH₃ photosynthesis. A high NH₃ formation rate from 238.6 to 587.3 μmol g⁻¹h⁻¹ is recorded under light irradiation intensity from 100 to 500 mW cm⁻², being remarkably higher than reported state-of-the-art photo-NRR systems under similar conditions. The superior performance is related to that solid–liquid spatial separation aids satisfactory light response, and the plasmon resonance accelerates the surface reaction dynamics, resulting in excellent solar-to-matter conversion and reversible active sites utilization.