Light-driven ammonia synthesis from nitrogen and hydrogen

Abstract

Ammonia (NH3) is a crucial commodity chemical in the global chemical industry. Conventionally, its production relies heavily on the Haber-Bosch process, which requires fossil energy while operating under high temperatures (400–500 °C) and pressures (100-200 atm). However, recent advancements in solar-driven ammonia synthesis have emerged as a promising alternative, enabling the conversion of nitrogen (N2) to NH3 under milder reaction conditions. This review summarizes the latest developments in photocatalytic ammonia synthesis from N2 and hydrogen (H2), with particular emphasis on the critical and unique role of light in enhancing catalytic performance through various mechanisms. We consolidate diverse engineering strategies aimed at optimizing photocatalytic active sites, thereby maximizing the effects of light to improve ammonia synthesis efficiency. By integrating these discussions, this review offers valuable insights into the design principles of effective photocatalysts, and addresses the prospects and challenges of harnessing solar energy for ammonia production.