Facile and template-free strategy to construct N, P co-doped porous carbon nanosheets as a highly efficient electrocatalyst towards oxygen reduction reaction

Two-dimensional (2D) porous carbon nanomaterials are of great interest for various applications in the field of energy conversion and storage. The development of efficient metal-free electrocatalysts for oxygen reduction reaction (ORR) with cost-efficient and simple approach still remains a significant challenge. Herein, we report a facile and template-free strategy to construct N, P co-doped porous carbon nanosheets (NPPC) by pyrolysis of calcium gluconate as carbon support and phosphonitrilic chloride trimer as the source N and P. The resultant NPPC, as metal-free electrocatalyst for ORR, exhibits outstanding electrocatalytic performance with a more positive half-wave potential of 0.87 V, longer durability and superior tolerance to methanol than those of commercial Pt/C in alkaline solution. Excellent ORR properties are contributed from the synergistic effect of abundant active sites of N, P and defects distributed in the carbon framework and 2D hierarchical pore morphology. Impressively, it is promising to inspire a general route for large-scale and facile synthesis of 2D porous carbon nanomaterials for application in new energy devices.