AcesExperimental and theoretical study on photocatalytic nitrogen reduction catalyzed by Fe doped MoO2

Transition metal oxides are suitable for photocatalytic nitrogen reduction (pNRR) due to their properties of narrow band gap and high energy density. Still, it is also limited by the defects of high photogenerated carrier recombination and low adsorption capacity of nitrogen molecules, which hinder the further improvement of the activity. For high carrier recombination and low activation rate of the nitrogen molecule, herein, Fe-doped MoO2 catalyst (Fe−MoO2) was synthesized for pNRR. Combined with the experimental characterization and theoretical calculation, it shows that the doping of Fe atoms, one hand, improves the conduction band position of MoO2 and enhances the reduction ability, which is favorable to nitrogen reduction. On the other hand, it not only enhances the adsorption of Mo sites and N2 molecules, but also changes the surface electronic structure and promotes the electron transfer from MoO2 to Fe sites, and the two act synergistically to adsorb and activate nitrogen more effectively. The activity of Fe−MoO2 for pNRR is as high as 96.62 μmol g−1h−1, which is about 2.5 times that of pristine MoO2, and the activity decreases by only 10% after three cycles.