Ultrasmall Cu3N Nanoparticles: Surfactant-Free Solution-Phase Synthesis, Nitridation Mechanism, and Application for Lithium Storage

New chemical pathways are of fundamental interest for materials synthesis. Here, we report a novel surfactant-free, solution-phase, low-temperature route to crystalline, ultrasmall (similar to 2 nm) Cu3N nanoparticles via a one-step reaction between copper(II) methoxide and benzylamine. We propose a reaction mechanism for Cu3N formation based on the gas chromatography-mass spectrometry (GC-MS) analysis of the organic reaction byproducts. The reaction pathway involves reduction of the Cu(II) to Cu(I) by benzylamine, in situ generation of ammonia, and finally, the reaction between Cu(I) and ammonia to form Cu3N. We tested the Cu3N nanoparticles as an anode material for Li-ion batteries (LIBs). According to cyclic voltammetry, the Cu3N nanoparticles quickly undergo a phase transformation to Cu2O, but then stably deliver a capacity of similar to 290 mAh/g at 1 A/g in the following 150 cycles.