Preferred Experimental Practices for Photocatalytic Nitrogen Fixation

Ammonia is synthesized through the Haber-Bosch process, and has the highest carbon footprint of any synthetic chemical commodity. This prompts the need for green alternatives to meet net-zero goals in the chemical sector. Photocatalytic conversion of nitrogen to ammonia is one such alternative gaining attention. The current progress in photocatalytic nitrogen reduction suggests, however, that there exists a large gap in performance, before commercial use is viable. One of the major challenges is that highly active photocatalysts have not yet been developed. Furthermore, the development of photocatalysts is greatly hindered by false positive or non-reproducible data. This is because the current photocatalyst produce very low ammonia concentration, therefore the ammonia measurement can be easily affected by adventitious ammonia from the environment. Here, we will describe the current known causes of non-reproducible results in photocatalytic nitrogen fixation literature. We also will present the solution to mitigate these false positive results. Finally, we highlight the main challenges that remain to be overcome in this field. We aim to help researchers design more reliable experiments and inspire practical research in developing photocatalytic nitrogen fixation.