From Structure to Solar Reactivity: Unraveling the Photocatalytic Ammonia Production on Perovskite Platforms

The growing need to reduce the energy demand and environmental footprint of conventional ammonia (NH 3 ) production has stimulated intensive research into various approaches for nitrogen (N 2 ) fixation. Photocatalytic N 2 fixation has attracted particular attention as an energy-efficient pathway for NH 3 synthesis, as this process utilizes renewable sunlight, abundant N 2, and water to drive the reaction in the presence of suitable catalytic materials. Consequently, substantial efforts have been devoted to the rational design and development of advanced materials with improved photocatalytic activity and stability. This review comprehensively analyzes recent breakthroughs in perovskite-based materials that have surfaced as unconventional yet promising photocatalysts for NH 3 production. A systematic classification of diverse perovskite materials based on their structural and compositional variations has been made, with a specific emphasis on how structural modifications and compositional tuning maximize important aspects such as N 2 adsorption and activation, charge carrier dynamics, and reaction selectivity. In addition, the mechanistic insights into biological and photocatalytic N 2 fixation and different methods for NH 3 quantification have also been included. The review concludes by outlining advances and future directions in process optimization, reactor design, and scalability, highlighting that the highest reported solar to NH 3 conversion efficiency (STA ∼0.3%) represents a significant step toward practical solar fertilizer systems. It is anticipated that the findings presented in this review will serve as a foundation for the rational design of next-generation perovskite photocatalysts, inspiring further investigations into their catalytic mechanisms and broadening their applicability in photocatalysis.