Boosted electrocatalytic activity of nitrogen-doped porous carbon triggered by oxygen functional groups

The development of high-performance, low-price and durable doped carbon-based materials as multifunctional oxygen reduction reaction and oxygen evolution reaction catalysts is of great significance for the sustainable energy conversion devices. Adopting zinc zeolitic imidazolate framework and graphitic carbon nitride as nitrogen-sources and templates, we herein design a facile route to fabricate an oxygen (6.11%) functionalized and heavy nitrogen (23.54%) doped porous carbon (NOC-800) with high graphitization degree, high surface area and total pore volume. Electrochemical measurements indicate that as-obtained NOC-800 sample has satisfactory multifunctional oxygen-involving electrocatalytic properties in alkaline media, showing an onset and half-wave potential of -0.141 and -0.249 V vs. Ag/AgCl for oxygen reduction and an overpotential of 377 and 448 mV at 10 and 50 mA cm^-2 for electrocatalytic oxygen evolution, respectively, even comparable to commercial RuO₂ catalyst and majority of present mainstream metal-free catalysts. Moreover, the desirable stability of NOC-800 catalyst for both oxygen reduction and oxygen evolution reaction is also demonstrated. Combined with the analysis and discussion of the physicochemical characterization and electrochemical measurements, it is proposed and highlighted that oxygen functional groups introduced into nitrogen-doped carbon profitably contributes to high-efficiency overall oxygen-involving electrocatalytic activities.