Synthesis and formation mechanism of pyramidal Cu3N microcrystal in supercritical fluids

Cu3N microcrystals were synthesized by a supercritical MeOH-NH3 technique with copper oxide and NH3 as copper and nitrogen source, respectively. The influence of reaction temperature on the fabrication of Cu3N particles was studied. The microstructures of products were characterized by XRD, SEM, FTIR, TG-DTA and XPS. Results show that product compositions depend greatly on the reaction temperatures and highly pure phase of Cu3N can be obtained at 250 °C. The as-prepared Cu3N displays a unique pyramidal morphology and the average edge length is 3–5 μm. Furthermore, the synthetic mechanism of Cu3N is also proposed.