Plasma-assisted nitrogen fixation in nanomaterials: fabrication, characterization, and application

Nitrogen fixation is a topic of continuing interest to researchers from generation to generation. Owing to the unique characteristics of plasma, its application to nitrogen fixation has recently attracted attention in the distributed chemical manufacturing field, i.e., making fertilizers on site. The incorporation of nitrogen as either 'lattice nitrogen' or 'chemical nitrogen', composing functional groups through plasma technology to form nitrogen-containing nanomaterials, is of great importance, since various properties or new functionalities can be achieved for nanomaterials with suitable nitrogen content. This review looks at the state of the art. Firstly, based on generated N-containing nanomaterials such as nitrides, carbonitrides, oxynitrides, oxycarbonitride, and N-doped/implanted nanostructures, the developed plasma-assisted processes and typical cases are classified and displayed. Possible mechanisms related to the N-fixation process using NH3 and N2 as the nitrogen source are discussed. The most commonly used techniques for material characterization are introduced, and representative examples are provided for a better understanding of the analytical tools. Important applications of the N-containing nanomaterials are enumerated, with the purpose of demonstrating their functionalities and potential uses. Finally, the outlook for future research in this field is given.