N-Doped Carbon Quantum Dots/Reduced Graphene Oxide Improves the Utilization of Platinum in Oxygen Reduction Reaction

Abstract

We demonstrated a one-step hydrothermal polyol reduction technique to produce platinum (Pt) and N-doped carbon quantum dots (N-CDs) co-loaded with reduced-graphene oxide (Pt@N-CDs/RGO). The electrochemical performance of commercial Pt/C, and Pt@N-CDs/RGO in 0.5 M H₂SO₄ electrolyte was compared under the Pt amount (20wt%). Pt@N-CDs/RGO exhibits ultra-high electroactivity and durability for oxygen reduction reaction (ORR). The electrochemically active surface area (ECSA) can be achieved to 124.8 m²/g, which is 1.65 times higher than that of commercial Pt/C. Pt@N-CDs/RGO shows an onset potential (E_onest) of 1.071 V, a half-wave potential (E_1/2) of 0.83 V, and a high transfer electron number of 3.97 at 0.4 V. Additionally, Pt@N-CDs/RGO exhibits significant long-term stability with 12 mV offset (1.4%) at E_1/2 after 1000 cycles. These performance improvements are owed to the edge defects of N-CDs, which enhance the utilization of Pt. The existence of edge defects in N-CDs provides a novel method for promoting the sustainable development of PEMFCs.

Keywords

carbon dots / platinum nanoparticles / electrocatalysis / ORR / stability

RIGHTS & PERMISSIONS

Wuhan University of Technology and Springer-Verlag GmbH Germany, Part of Springer Nature