Surface-defect-engineered photocatalyst for nitrogen fixation into value-added chemical feedstocks

Abstract

Efficient dinitrogen (N₂) utilization using nitrogen-containing compounds such as ammonia (NH₃) and nitrates, which are essential materials for modern fertilizers, medicines, etc., is important to the development of human society. However, the industrial synthesis of NH₃ and nitrates requires high temperatures and pressures along with massive energy consumption. In this context, photocatalytic N₂ fixation is regarded as an alternative promising strategy for the synthesis of nitrogen-containing compounds under ambient conditions. In this minireview, fundamental photocatalytic N₂ fixation mechanisms, including N₂ photoreduction to NH₃ and photooxidation to nitrates, are initially elaborated. Then, we focus on the effects of surface defect engineering (e.g., surface vacancies and heteroatom dopants) over semiconductor-based photocatalysts for efficient N₂ fixation. Finally, we cast a personal perspective on the possible future challenges faced by defect-containing photocatalysts for N₂ fixation. We hope that this minireview can shed light on the further development of rational designs of defect-containing photocatalysts toward efficient N₂ fixation into diverse value-added chemical feedstocks.