Enhancing N₂ Fixation Activity by Converting Ti₃ C₂ MXenes Nanosheets to Nanoribbons

Metal carbides M₂ C (MXenes) with two-dimensional (2D) structure have been indicated as promising materials for N₂ fixation, with the activity being related to edge planes. Here, it is instead demonstrated that the transformation from a 2D- (nanosheets) to a 3D-type nanostructure (nanoribbons) leads to a significant enhancement of the N₂ fixation activity due to the formation of exposed Ti-OH sites. A linear relationship is observed between ammonia formation rate and amount of oxygen on the surface of Ti₃ C₂ MXene.