Quickly Generated N, Co Codoped Porous Graphene from Waste Biomass at Low Temperature for an Effective Oxygen Reduction Reaction

Porous carbon nanomaterials derived from waste biomass have attracted a great deal of attention as high-performance nonprecious metal electrocatalysts for the oxygen reduction reaction (ORR). However, the production of porous carbon nanocatalysts usually requires a high temperature and a long time. Here, we propose a fast low-temperature strategy to obtain nonmetal and transition metal codoped porous graphene with a tunable hole structure from waste seed husk via a triple KCl/LiCl/ZnCl₂ molten salt system. The codoped porous graphene exhibited a large specific surface area, sufficient microporous/mesoporous channels, and equally distributed elements, resulting in excellent catalytic activity, long-term stability, and methanol tolerance for ORR in alkaline media. In particular, the prepared PG-600-N,Co catalyst retains 97.1% of its initial current density after a chronoamperometric response test of 65 000 s, which is much better than the commercial Pt/C catalyst. Moreover, PG-600-N,Co can be applied as an anode in lithium-ion batteries (LIBs) and exhibits outstanding performance. In particular, it shows a specific capacity of 404 mAh g^-1 after 100 cycles at a current density of 1 A g^-1. Our work offers a feasible massive synthesis of regulated codoped porous graphene as efficient ORR nanocatalysts and anodes for LIBs.