Few-layer graphdiyne doped with sp-hybridized nitrogen atoms at acetylenic sites for oxygen reduction electrocatalysis

Abstract

The oxygen reduction reaction (ORR) is a fundamental reaction for energy storage and conversion. It has mainly relied on platinum-based electrocatalysts, but the chemical doping of carbon-based materials has proven to be a promising strategy for preparing metal-free alternatives. Nitrogen doping in particular provides a diverse range of nitrogen forms. Here, we introduce a new form of nitrogen doping moieties -sp-hybridized nitrogen (sp-N) atoms into chemically defined sites of ultrathin graphdiyne, through pericyclic replacement of the acetylene groups. The as-prepared sp-N-doped graphdiyne catalyst exhibits overall good ORR performance, in particular with regards to peak potential, half-wave potential and current density. Under alkaline conditions it was comparable to commercial Pt/C, and showed more rapid kinetics. And although its performances are a bit lower than those of Pt/C in acidic media they surpass those of other metal-free materials. Taken together, experimental data and density functional theory calculations suggest that the high catalytic activity originates from the sp-N dopant, which facilitates O adsorption and electron transfer on the surface of the catalyst. This incorporation of chemically defined sp-N atoms provides a new synthetic route to high-performance carbon-based and other metal-free catalysts.

Graphdiyne: A New Photocatalytic CO2 Reduction Cocatalyst

“…[29][30][31] Particularly, the discovery of graphene has raised a wave of new research on a range of 2D materials, e.g., phosphorene, transition metal dichalcogenides and hexagonal boron nitrides. [34,35] More importantly, electrons in the high-energy acetylenic linkages are prone to delocalization to reach the most stable state. [32,33] Each benzene ring is connected with butadiyne linkages, endowing GDY with superior electronic conductivity, structural flexibility, and chemical stability.…”

Electronic Structure Engineering of LiCoO2 toward Enhanced Oxygen Electrocatalysis

“…[27,[29][30][31][32][33][34][35] However, its catalytic activity still needs to be enhanced to meet the requirements of practical applications. [39][40][41][42][43] Moreover, the electronic conductivity of the catalyst system is also a vital factor for fast Developing low-cost and efficient electrocatalysts for the oxygen evolution reaction and oxygen reduction reaction is of critical significance to the practical application of some emerging energy storage and conversion devices (e.g., metal-air batteries, water electrolyzers, and fuel cells). [36] Creating defects, modulating the electronic structure, and tuning the lattice strain are significant strategies to enhance the intrinsic activity of catalysts.…”

“…Toward the intelligent design of high performance electrocatalysts, two general strategies (enhancing the intrinsic activity and increasing the number of active sites) have been applied to improve the activity of targeted electrocatalysts. [39][40][41][42][43] Moreover, the electronic conductivity of the catalyst system is also a vital factor for fast Developing low-cost and efficient electrocatalysts for the oxygen evolution reaction and oxygen reduction reaction is of critical significance to the practical application of some emerging energy storage and conversion devices (e.g., metal-air batteries, water electrolyzers, and fuel cells). [2,8] Nanostructure engineering by reducing the material's dimension and size is the most commonly deployed approach to increase the exposure of active sites.…”

A Universal Strategy for Constructing Seamless Graphdiyne on Metal Oxides to Stabilize the Electrochemical Structure and Interface

“…[3,7] Recent studies have shown that carbon components are necessary to improve the activity, conductivity, and stability of MOs, [8,9] and the all-carbon modifications are definitely more stable than other inorganic ones. Although, some prominent properties of GDY have been explored in electrochemical actuator, catalysts, LIB anodes, and supercapacitor electrodes, [17][18][19][20][21] itsThe structural and interfacial stabilities of metal oxides (MOs) are key issues while facing the volumetric variation and intensive interfacial polarization in electrochemical applications, including lithium-ion batteries (LIBs), supercapacitors, and catalysts. Until now, the efficient construction of such multifunctional interfaces is a challenging issue, because the prevailing all-carbon materials are commonly prepared under high temperature and cannot be seamlessly grown on the MOs by any top-down and bottom-up strategies.…”

“…However, the seamless protection on the primary particles of MOs are what we are more interested in, because it can be clearly noticed that the NiCo-R, NiCo-W, and NiCo-F are secondary structures (Figures S10 and S11, Supporting Information), assembled by the primary nanoparticles about 5 nm (Figures S10b and S11b, Supporting Information). [19,39,40] The inserted image in Figure 2j is the mode of highly crystalline ABC-stacked GDY. However, the interfacial protection on the primary particles is a challenging issue in the traditional methods.…”