Boosting defective carbon by anchoring well-defined atomically dispersed metal-N4 sites for ORR, OER, and Zn-air batteries

Experimental and computational studies show that topological defect and FeN4 site in carbon materials would deliver high performances for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Either defect or FeN4 site attracts numerous discussion, however, the synergetic effect between them is hardly explored. Herein, we design a facial strategy to synthesize N,P-doped defective carbon nanosheets first (N,P-DC), then cover doped sites with well-define metal-N-4 macrocyclic molecules (FePc@N,P-DC) through non-pyrolysis process. The defective carbon boosts the high spin state of Fe center, thus brings superior ORR performances with the half-wave potential of 0.903 V and excellent cycling-life stability in alkaline media. Theoretical calculations show that the overpotential of FePc@N,P-DC for ORR is 0.52 V, much lower than 0.80 V (N,P-DC). Interestingly, the OER activity is simultaneously improved. This metal-Pc@defective carbon hybrid opens a door to develop electrocatalysts combining atomically metal-N-4 sites with topological defect towards diverse energy conversion type.