Heteroatom embedded graphene-like structure anchored on porous biochar as efficient metal-free catalyst for ORR

Efficient biomass-derived carbon have large potential as alternative to metal-based catalysts for oxygen reduction reaction (ORR). This study demonstrates a feasible strategy to largely prepare enteromorpha (EP) derived biochar with N, S embedded graphene-like structure anchored, which is firstly used as efficient metal-free electrocatalyst for ORR. Omitting the selection and classification of raw material as well as further additional activation and/or modification by dopants, the preparation process was merely adjusted via pyrolysis and acid etching. The obtained catalyst with low content of N (3.80 at%), S (1.00 at%) and large surface area (778.2 m 2  g −1 ) exhibited an onset potential of 0.95 V vs RHE in a four electron pathway, which showed superior stability and durability compared to that of commercial Pt/C catalyst. The outstanding performance of the catalyst is expected to be a potential candidate for sustainable and large-scale industrial energy conversion and storage processes in the near future.