Melamine-Induced N,S-Codoped Hierarchically Porous Carbon Nanosheets for Enhanced Electrocatalytic Oxygen Reduction

Exploring an efficient strategy to enhance the catalytic oxygen reduction performance of carbon-based catalysts is of great significance in the field of electrocatalysis. In this work, through a facile polymerization-carbonization approach under the regulation of melamine, N,S-codoped hierarchically porous carbon nanosheets with controllable morphology are fabricated by using polyaniline as the precursor. The resultant catalysts have favorable features of the synergetic effect of N,S co-doping and the advanced structural property with high specific surface area and hierarchical pore structure, contributing to an encouraging onset potential (E-onset = 0.94 V) in alkaline media, comparable to that of Pt/C catalysts, as well as excellent electrochemical stability and methanol tolerance. By rationally adjusting the experimental parameters, the mechanism of melamine on the formation of final porous nanosheet structure during high-temperature pyrolysis is clarified, and the optimal experimental conditions for the superior catalysts are also discussed. Furthermore, a rechargeable Zn-air battery constructed with the resulting materials exhibits desirable performance with low charge-discharge gap and impressive life-span. This contribution would supply some novel inspiration to design carbon-based materials with desired features for energy-related technologies.