Hierarchical Metal-Free Nitrogen-Doped Porous Graphene/Carbon Composites as an Efficient Oxygen Reduction Reaction Catalyst

Abstract

Hierarchical nitrogen-doped porous graphene/carbon (NPGC) composites were fabricated by a simple and nontemplate method. The morphology characterizations demonstrate that reduced graphene oxide was successfully coated by the carbon derived from glucose, and a well-organized and interpenetrated hierarchical porous structure of NPGC was formed after pyrolysis at 950 °C. Notably, the prepared material, denoted as NPGC-950, has superlarge specific surface area (1510.83 m(2) g(-1)) and relatively high content percentage of pyridinic and graphitic nitrogen. As an efficient metal-free electrocatalyst, NPGC-950 exhibits a high onset potential (0.91 V vs RHE) and a nearly four-electron pathway for oxygen reduction reaction in alkaline solution as well as stronger methanol tolerance and better long-term durability than commercial Pt/C. In view of these excellent features, the obtained hierarchical N-doped metal-free porous carbon material is a promising catalyst for oxygen reduction reaction and could be widely applied in industry.

Hydrogen Evolution Activity of Ruthenium Phosphides Encapsulated in Nitrogen‐ and Phosphorous‐Codoped Hollow Carbon Nanospheres

“…Notably, the peak at 132.6 eV for P−C implies the successful insertion of P into the N‐doped carbon hollow spheres. In the N 1s region (Figure e), the peaks at 398.6, 400.3, 401, and 402.5 eV can be indexed to pyridinic, graphitic, pyrrolic, and oxidized N atoms, respectively . The doping of N and P, which have a low electronegativity, into the active phase and amorphous carbon matrix can vary the electronic structures effectively to promote the HER kinetics, which leads to the intrinsically improved HER activity .…”

Solvothermal access to rich nitrogen-doped molybdenum carbide nanowires as efficient electrocatalyst for hydrogen evolution reaction

“…In the N 1s XPS spectrum ( Fig. 3g and h), the binding energy peaks at 395.0, 398.6 and 400.1 eV belong to NeC group, pyridinic N and pyrrolic N, respectively [39,40]. However, as for rich N-doped Mo 2 C, the atomic ratio of NeC increases from 44.6% to 56.6% compared with those of N-doped Mo 2 C, which may be due to the doping of nitrogen by solvothermal treatment.…”

Hard Carbons for Sodium‐Ion Battery Anodes: Synthetic Strategies, Material Properties, and Storage Mechanisms

“…[115] Structurald ifferences from traditional hard carbons arise mainlyt hrough the presence of interdomain micro-and mesopores. [133] Doping of various heteroatoms and their codoping have been shown to enhance the activity,r elative to undoped systems. The application of hard carbons in the oxygen reduction reaction( ORR), supercapacitors, gas storage, and water purification have received tremendous prominence.…”