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

Abstract

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 (∼2 nm) Cu 3 N nanoparticles via a one-step reaction between copper(II) methoxide and benzylamine. We propose a reaction mechanism for Cu 3 N 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 Cu 3 N. We tested the Cu 3 N nanoparticles as an anode material for Li-ion batteries (LIBs). According to cyclic voltammetry, the Cu 3 N nanoparticles quickly undergo a phase transformation to Cu 2 O, but then stably deliver a capacity of ∼290 mAh/g at 1 A/g in the following 150 cycles.

An Artificial Solid Electrolyte Interphase with High Li‐Ion Conductivity, Mechanical Strength, and Flexibility for Stable Lithium Metal Anodes

“…The Coulombic efficiency can be improved to above 97.4% with a current density up to 1 mA cm −2 in corrosive carbonate electrolyte on copper (Cu) current collector and if applied on porous Li-coated polyimidezinc oxide electrode (Li-coated PI-ZnO), the coating rendered a 40% increase in cycle life when paired with Li titanate (LTO). [30,31] Fortunately, the electrochemical potential of the Li metal anode will usually not exceed the decomposition voltage (≈0.5 V theoretically) of Li 3 N under normal operation conditions, [32] which guarantees the validity of our proposed coating as a Li-ion conducting artificial SEI on Li metal electrode. Cu 3 N nanoparticles with a size of sub-100 nm were synthesized via a facile one-step reaction between Cu(II) methoxide (Cu(OMe) 2 ) and benzylamine ( Figure S1, Supporting Information).…”

“…[11][12][13] For the first time, the approach minimized the volumetric change at the whole electrode level during Li plating/stripping. [30] The resulting nanoparticles can be readily dispersed in tetrahydrofuran (THF) with SBR to form a stable colloidal solution, which can then be applied on the Li surface via doctor blade casting or drop casting to afford a conformal protection layer. Other an ideal SEI.…”

Mechanistic Aspects in the Formation, Growth and Surface Functionalization of Metal Oxide Nanoparticles in Organic Solvents

“…Accordingly, one could assume that benzylamine might be able to act as nitrogen donor for the formation of metal nitrides. Unfortunately, most of the reactions in benzylamine still result in metal oxide nanoparticles with the only exception being copper nitride …”

“…In contrast to titanium isopropoxide, the reaction between the copper alkoxide Cu(OCH 3 ) 2 and benzylamine indeed led to the formation of copper nitride rather than copper oxide . GC‐MS data indicated that initially a benzylamine molecule reacted with two Cu(OCH 3 ) 2 to yield methanol, CuOCH 3 and benzenemethanimine (Scheme , Equation (1)).…”

A general nonaqueous sol-gel route to g-C3N4-coupling photocatalysts: the case of Z-scheme g-C3N4/TiO2 with enhanced photodegradation toward RhB under visible-light

“…Among the organic solvents used in surfactant-free nonaqueous methods, benzyl alcohol and its derivatives, first reported by Niederberger et al ., are the most brilliant2526. Through the versatile solvents, numerous semiconductors including nitrides2728, sulfides29, binary and ternary oxides3031 have been effectively synthesized. It covers most of the semiconductors used in heterogeneous photocatalysis.…”