Ultrathin Nitrogen‐Doped Holey Carbon@Graphene Bifunctional Electrocatalyst for Oxygen Reduction and Evolution Reactions in Alkaline and Acidic Media

Abstract

Efficient nonprecious‐metal oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) electrocatalysts are key for the commercial viability of fuel cells, metal–air batteries, and water‐splitting systems. Thus, high‐performance ORR and OER electrocatalysts in acidic electrolytes are needed to support high‐efficiency proton exchange membrane (PEM)‐based systems. Herein, we report a new approach to design and prepare an ultrathin N‐doped holey carbon layer (HCL) on a graphene sheet that exhibits outstanding bifunctional ORR/OER activities in both alkaline and acidic media. The edge sites of HCL are utilized to achieve selective doping of highly active pyridinic‐N. The sandwiched graphene sheet provides mechanical support, stabilizes HCL structure and promotes charge transfer. The synergetic effect of the catalyst structure overcomes the drawbacks of holey graphene approaches. The resulting ORR and OER performances are equal to or better than the top‐ranked electrocatalysts.

Ultrafine Defective RuO2 Electrocatayst Integrated on Carbon Cloth for Robust Water Oxidation in Acidic Media

“…[35][36][37] As a result, the charge and mass transport of catalyst electrodes will inevitably be comprised. Correspondingly, the size of Zn doped RuO 2 nanoparticles can also be reduced; 2) the Zn species can be readily removed by means of acid treatment so that some defects would be created and the particle sizes are further reduced.…”

NiFe Alloy Nanoparticles with hcp Crystal Structure Stimulate Superior Oxygen Evolution Reaction Electrocatalytic Activity

“…And Na toms are evenly doped in carbon shells as shown in Figure 1g,h.A ccording to Raman spectra in Figure S5, the two characteristic peaks at 1350 cm À1 (D-band) and 1580 cm À1 (G-band) in hcp-NiFe@NC were observed, corresponding to disordered and graphitic carbon. [18] And pyridinic-N occupies the dominant portion in carbon shell (Table S1). [15] X-ray photoelectron spectroscopy (XPS) was applied to determine the surface composition and chemical state of each element of hcp-NiFe@NC.F ive elements including Ni, Fe,C , N, and Oare identified from the XPS full spectra in Figure S6.…”

An Ultrasensitive Electrochemical Immunosensor for Nonylphenol Leachate from Instant Noodle Containers in Southeast Asia

“…The intensity ratio of the D and G bands ( I D / I G ) is usually used to evaluate the degree of reduction of graphene . As shown in Figure B, GO has two characteristic Raman bands (1340 and 1605 cm −1 ), which correspond to the D and G bands, respectively . After combination with PEI and hydrazine reduction, the I D / I G ratio increased from 0.93 to 1.05.…”