|Title||Three-Dimensional Phosphorus-Doped Graphitic-C3N4 Self-Assembly with NH2-Functionalized Carbon Composite Materials for Enhanced Oxygen Reduction Reaction|
|Publication Type||Journal Article|
|Year of Publication||2016|
|Authors||Qiu, Y, Xin, L, Jia, F, Xie, J, Li, WZ|
|Type of Article||Article|
|Keywords||cathode catalysts, chemistry, fuel-cells, Graphene, high electrocatalytic activity, hydrogen evolution, Materials Science, metal-free electrocatalysts, nanosheets, nitride, nitrogen, performance, visible-light|
Oxygen reduction reaction (ORR) is the major reaction that occurs at the cathodes of fuel cells and metal-air batteries. Development of inexpensive, active, and durable heteroatom doped carbon-based ORR catalysts can lead to significant cost reduction of these electrochemical energy devices, which therefore has recently attracted enormous research attentions. This work reports a three-dimensional porous composite (P-g-C3N4@NH2-CB) for the highly efficient ORR catalyst. P-g-C3N4@NH2-CB was prepared by mixing phosphorus-doped graphitic carbon nitride nanosheets (P-g-C3N4 NSs) with NH2-functionalized carbon black (NH2-CB) via a novel self-assembly approach. The NH2-CB was rationally chosen as the spacer that enables the self-assembled with the P-g-C3N4. NSs driven by the electrostatic interaction. The intercalation of NH2-CB induces the transformation of 2-D P-g-C3N4 NSs into a 3-D composites material of higher surface area, thereby exposing more ORR active sites. The P-g-C(3)N4@NH2-CB exhibited a remarkable ORR activity with an electron transfer number of 3.83 and Tafel slope of 89 mV dec(-1) in alkaline electrolyte, which is comparable to the ORR performance on Pt/Vulcan XC-72. It is found that the incorporated P atoms as well as employing NH2-CB spacer not only reduces the overpotential of ORR, but also enhances the ORR activity of carbon nitride-based materials, owing to the synergistic effect between P and N in tri-s-triazine rings of carbon nitrides and the optimum interaction between the oppositely charged P-g-C3N4 and NH2-CB.
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