Optimal Configuration of N‐Doped Carbon Defects in 2D Turbostratic Carbon Nanomesh for Advanced Oxygen Reduction Electrocatalysis

Abstract

The charge redistribution strategy driven by heteroatom doping or defect engineering has been developed as an efficient method to endow inert carbon with significant oxygen reduction reaction (ORR) activity. The synergetic effect between the two approaches is thus expected to be more effective for manipulating the charge distribution of carbon materials for exceptional ORR performance. Herein we report a novel molecular design strategy to achieve a 2D porous turbostratic carbon nanomesh with abundant N‐doped carbon defects (NDC). The molecular level integration of aromatic rings as the carbon source and urea units as the N source and sacrificial template into the novel precursor of polyurea (PU) promises the formation of abundant carbon edge defects and N doping sites. A special active site—a carbon edge defect doped with a graphitic valley N atom—was revealed to be responsible for the exceptional ORR performance of NDC material.

Defective Carbon Derived Using a Dissolution–Recrystallization Strategy for Oxygen Reduction Electrocatalysis

“…As shown in Figure e, the four kinds of carbon bonding configurations are D (at 1350 cm –1 ), D″ (at 1496 cm –1 ), T (at 1200 cm –1 ), and G (at 1590 cm –1 ). The D″ band is mainly attributed to five-membered rings in graphene sheet structures. , The T band is mainly attributed to disordered graphitic lattice, which includes carbon atoms outside of the graphene network. − It is shown in Figure e that compared with CNRs and CNPs, the ratio of D″ carbon in d-CNRs is significantly higher, which meant that d-CNRs contain a higher ratio of five-membered rings. The relative intensity ratio of the D band and G band ( I D / I G ) is considered as the reflection of disordered structure density in carbon materials.…”

Atomically dispersed Co in a cross-channel hierarchical carbon-based electrocatalyst for high-performance oxygen reduction in Zn–air batteries

“…32 The ratios I D / I G of CoSA@NPC, NS-NPC and NI-NPC are 1.08, 1.05, and 1.04, respectively, indicating the highest defect level of CoSA@NPC. 33 Nitrogen adsorption–desorption measurement was used to evaluate the porosity of CoSA@NPC, NS-NPC and NI-NPC (Fig. S7 and Table S2†).…”

A Self-powered Aptasensor for Isocarbophos Determination Based on Nanozyme-catalytic Photoelectrochemical Fuel Cell

“…3A and 3B), the compact Fe-based spheres with an average diameter of 10-15 nm were encapsulated by thin turbostratic carbon shells with a line distance of 2-3 nm. The clear lattice fringes with an interplanar distance of 0.21 nm in the core corresponded to (211) facets of Fe 3 C which was reported as active species for ORR catalysis (Li et al 2015), the lattice distance of 0.38 nm corresponded to (002) facet of carbon in the shell, indicating the formation of turbostratic carbon structure, which was favorable to generate N-doped active sites (Lai et al 2020). Likewise, XRD pattern of Fe-N-C showed an obvious wide peak at 22.74° corresponding to (002) crystal face of turbostratic carbon, and diffraction peaks at 37.8°, 42.8°, 43.7°, 44.9°, 45.8°, 49.2° corresponding to the Fe 3 C (Fig.…”