Fe2N/S/N Codecorated Hierarchical Porous Carbon Nanosheets for Trifunctional Electrocatalysis

Construction of multifunctional highly active earth‐abundant electrocatalysts on a large scale is a great challenge due to poor control over nanostructural features and limited active sites. Here, a simple methodology to tailor metal–organic frameworks (MOFs) to extract highly active multifunctional electrocatalysts on a large scale for oxygen reduction (ORR), oxygen evolution (OER), and hydrogen evolution reaction (HER) is presented. The N, S codoped Fe2N decorated highly porous and defect‐rich carbon nanosheets are grown using MOF xerogels, melamine, and polyvinylpyrollidone. The resulting catalyst exhibits excellent activity for ORR with an onset (0.92 V) and half‐wave (0.81 V) potential similar to state‐of‐the‐art Pt/C catalysts. The catalyst also shows outstanding OER and HER activities with a small overpotential of 360 mV in 1 m KOH and −123 mV in 0.5 m H2SO4 at a current density of 10 mA cm−2, respectively. Excellent catalytic properties are further supported by theoretical calculations where relevant models are built and various possible activation sites are identified by first‐principles calculations. The results suggest that the carbon atoms adjacent to heteroatoms as well as Fe2–N sites present the active sites for improved catalytic response, which is in agreement with the experimental results.