Surveying the Synthesis, Optical Properties and Photocatalytic Activity of Cu3 N Nanomaterials

Abstract

This review addresses the most recent advances in the synthesis approaches, fundamental properties and photocatalytic activity of Cu3 N nanostructures. Herein, the effect of synthesis conditions, such as solvent, temperature, time and precursor on the precipitation of Cu3 N and the formation of secondary phases of Cu and Cu2 O are surveyed, with emphasis on shape and size control. Furthermore, Cu3 N nanostructures possess excellent optical properties, including a narrow bandgap in the range of 0.2 eV–2 eV for visible light absorption. In that regard, understanding the effect of the electronic structure on the bandgap and on the optical properties of Cu3 N is therefore of interest. In fact, the density of states in the d-band of Cu has an influence on the band gap of Cu3 N. Moreover, the potential of Cu3 N nanomaterials for photocatalytic dye-degradation originates from the presence of active sites, i.e., Cu and N vacancies on the surface of the nanoparticles. Plasmonic nanoparticles tend to enhance the efficiency of photocatalytic dye degradation of Cu3 N. Never-theless, combining them with other potent photocatalysts, such as TiO2 and MoS2, augments the efficiency to 99%. Finally, the review concludes with perspectives and future research opportunities for Cu3 N-based nanostructures.