Recent advances in wireless photofixation of dinitrogen to ammonia under the ambient condition: A review

Ammonia is the most necessitate and second largely produces chemical reagent worldwide to address the need of the fertilizer industry, as a precursor for many value-added chemicals and a competing source (17.6 wt% H₂) for the blooming hydrogen economy. Although N₂ constitutes 78.09 % of the earth's atmosphere, however, its conversion to ammonia is strenuous because of its non-polar and triple bond character. To address the burgeoning demand, ammonia is typically synthesized via the conventional energy and capital intensive Haber-Bosch technique utilizing natural gas and releasing tons of (CO₂) to the environment. On this basis, cost-effective photon-driven dinitrogen reduction reaction (NRR) is aroused thriving attention as a sustainable and eco-friendly process for ammonia production under ambient conditions. Yet, the photocatalytic ammonia production is not up to the mark for industrial application due to low conversion rate, less catalytic selectivity, ambiguous mechanism, and limited faradic or solar-to-chemical efficiency. Further, the NRR activity of a catalyst essentially depends upon its electronic and surface texture; hence the fabrication of advanced materials is of paramount interest to enhance the performance. The present review covers the underlying mechanism of N₂ photoreduction, prevailing theories, different catalytic engineering techniques, various detection methods, and critical challenges encountered in the theme of photofixation of dinitrogen to ammonia. Additionally, the overarching goal of this review is to bestow an outline of recent research articles in earmarking high-caliber photocatalytic systems and hence planting a strong foundation to ensure the succeeding improvement in this promising and hastily stretching field of dinitrogen photofixation research.