Enhanced N2 photofixation activity of flower-like BiOCl by in situ Fe(III) doped as an activation center.

Photocatalytic nitrogen fixation has been considered to be a safe, green, eco-friendly, and sustainable technology. However, photoinduced activation of inert dinitrogen is an important factor hindering the development of this technology. Herein, in-situ Fe3+ doped flower-like BiOCl with highly active sites exposure was prepared by a solvent thermal method, which has excellent performance of N2 photofixation. Compared with virgin BiOCl with no nitrogen fixation activity, Fe-BiOCl reached 30 μmol·L-1·h-1 ammonia evolution rate under simulated sunlight without any sacrificial reagent. Characterization results demonstrated that the enhancement of N2 photofixation capacity was mainly attributed to the in-situ doped Fe3+ in BiOCl, the doped Fe3+ not only acts as a reaction center for N2 activation also as an "electron transfer bridge" trapping and migrating electrons from BiOCl to N2 molecules. Furthermore, the transformation of crystal facets from virgin BiOCl (001) to Fe-BiOCl (110) and (102) is more conducive for the exposure and accessibility of iron reactive sites. This work developed a potential strategy by in-situ introducing Fe3+ active sites in BiOCl semiconductor substrate, which establishes a good basis for the application of semiconductor catalysts in nitrogen fixation.