While the above-reported materials represent well-established photocatalysts, in the last years metal halide perovskites (MHPs) have demonstrated to be efficient and promising materials for various photocatalytic applications thanks to their unique features such as tunable band gap, high absorption coefficient, and long charge carrier lifetime and diffusion lengths, which are crucial for reducing recombination rates and enhancing photocatalytic efficiency. While MHPs have been extensively explored for several solar-related applications, such as photocatalytic H2 generation, photoreduction of CO2, and synthesis of organic molecules, their exploitation in the field of nitrogen photofixation is in its newborn era, with the first example, reporting the Cs2AgBiCl6/g-C3N4 heterojunction, recently published by our group, where it was proved that such system is capable, by properly tuning the heterojunction composition, to carry out both H2 photogeneration and N2 photofixation with active sites for this reaction present on the carbon nitride and with the perovskite acting to improve charge carrier management. While this paper represents the first demonstration of a MHPs-based heterojunction for ammonia photoproduction, the obtained rates were relatively low and the full exploitation of the potential of such systems for nitrogen photofixation has still to be demonstrated. Based on this preliminary results, we aimed at engineering optimized perovskite-based heterojunctions for nitrogen photofixation that could provide significant production rates and where the perovskite could itself provide active sites for the nitrogen reduction to ammonia.