Nitrogen-doped porous carbon nano-sheets (N-CNS) are synthesized by hydro thermal carbon coating of g-C3N4 nanosheets followed by high-temperature treatment in N-2. g-C3N4 serves as a template, nitrogen source, and porogen in the synthesis. This approach yields N-CNS with a high nitrogen content and comparable oxygen reduction reaction catalytic activities to commercial Pt/C catalysts in alkaline media.