Key Words:Doping (additives);Electric fields - Field emission - Graphene - Molar ratio - Morphology - Nanoparticles - Nanotubes - Photoluminescence - Synthesis (chemical)
Abstract:N-doped graphene nanotubes coated by amorphous SiO<inf>x(x=1-2)</inf> nanoparticles (N-doped GNTs@a-SiO<inf>x(x=1-2)</inf>NPs) were synthesized by a simple template-free one-step calcination method. The method not only possesses a simple synthesis process, but also protects the graphene nanotubes from damage caused by template removal. The characterization results show that amorphous SiO<inf>x(x=1-2)</inf> nanoparticles with a size of 20-40 nm were located on the surface of the N-doped graphene nanotubes. The product synthesized under the optimal molar ratio of raw materials (C<inf>3</inf>H<inf>6</inf>N<inf>6</inf>: Si/SiO<inf>2</inf> powders = 1 : 2) presents a lower turn-on electric field of 0.663 V μm⁻¹, and especially, a very low threshold electric field of 1.575 V μm⁻¹ (at 10 mA cm⁻² current density). Moreover, it also showed improved intensity of yellow-green emission compared with N-doped GNTs. The reason for the outstanding performance of N-doped GNTs@a-SiO<inf>x(x=1-2)</inf>NPs was attributed to the synergistic effect of N-doping, a large number of oxygen vacancy defects of SiO<inf>x(x=1-2)</inf>, and the unique morphology. The research results not only provide a new method for large-scale synthesis of N-doped GNTs@a-SiO<inf>x(x=1-2)</inf>NPs nanocomposites with excellent field emission properties and photoluminescence properties, but also lay the foundation for their applications in various fields.<br/> © The Royal Society of Chemistry.
Volume:7
Issue:13
Translation or Not:no