Boron and nitrogen co-doped carbon dots for boosting electrocatalytic oxygen reduction

Carbon dots (CDs) have become an emerging carbon nanomaterial for use in energy-conversion systems because of their large surface area and rapid electron transfer. Carbon dots (BN-CDs) doped with both boron and nitrogen were synthesized by a simple one-step electrochemical etching approach using low-cost petroleum coke as precursor. Compared with CDs doped with only B or N, BN-CDs showed an excellent four-electron oxygen reduction reaction (ORR) activity with a positive onset potential of 0.958 V and a large diffusion-limited current density of - 4.32 mA cm(-2). Furthermore, the long-term stability and methanol tolerance of BN-CDs were better than those of a commercial Pt/C catalyst. It was found by density functional theory (DFT) calculation that the co-doping of N and B promoted the adsorption of O-2 molecules in the ORR process. This work provides new insight into the rational design of carbon nanomaterials and their use in energy conversion.

Automated summary

This study synthesized carbon dots doped with both boron and nitrogen from low-cost petroleum coke, which showed better oxygen reduction reaction activity, stability, and methanol tolerance compared to carbon dots doped with only boron or nitrogen. Density functional theory calculations revealed that the co-doping of nitrogen and boron promoted the adsorption of O-2 molecules in the ORR process. This work provides new insights into the rational design of carbon nanomaterials for energy conversion applications.