Fe Enhanced Visible-Light-Driven Nitrogen Fixation on BiOBr Nanosheets

Photocatalytic conversion of nitrogen (N-2) to ammonia (NH3) requires strong binding of N-2 onto the catalyst surface and the generation of photoexcited electrons to activate the N equivalent to N bond. In this study, Fe is doped into BiOBr nanosheets, where the photoexcited electrons have enough energy to break the N equivalent to N bond. The presence of Fe induces the formation of oxygen vacancies (OVs) in its vicinity, making it a photoexcited electron-rich region. The reduced Fe species effectively donates its available 3d orbital electron into the pi N-N antibonding orbital to activate the adsorbed N-2. With Fe as the active site, the N-2 fixation rate of Fe-doped BiOBr is enhanced by eight times. This work provides a sustainable alternative for N-2 photofixation and strategies for the catalyst design.