Comprehensive analysis of catalysts, reaction mechanisms, and efficiency factors in photocatalytic nitrate-to-ammonia conversion

The ammonia industry plays a crucial role in various aspects of human progress and the global economy, particularly in fields such as fertilizers and the production of emerging clean fuels. The Haber-Bosch process, a commercially used method for ammonia production has significant environmental drawbacks and is economically challenging. The conversion of nitrates into ammonia can be considered as an alternative approach to address these challenges. Nitrates represent a prevalent toxic inorganic compound found in groundwater, posing significant health risks when present in high levels in drinking water. An emerging field of research, photocatalysis, harnesses solar energy and catalysts to convert nitrates into ammonia, offering environmentally sustainable and cost-efficient pathways. This review provides a thorough exploration of recent advancements in the reduction of nitrate to ammonia using photocatalytic technology. The discussion comprehends various aspects, including the detailed mechanism of ammonia production based on experimental and theoretical calculations, a detailed analysis of reported catalysts, factors affecting ammonia production, and potential areas for advancement based on previous research. Furthermore, this comprehensive review examines the challenges and prospects for future efforts essential for adopting photocatalysis for ammonia production from nitrate pollution.