Heterostructured Cu/CuO Nanoparticles Embedded within N-Doped Carbon Nanosheets for Efficient Oxygen Reduction Reaction

The development of cost-effective and highly efficient oxygen reduction reaction (ORR) electrocatalysts is an essential component of renewable clean energy technologies, such as fuel cells and metal/air cells, but remains a huge and long-term challenge. Here, novel heterogeneous Cu/CuO nanoparticles embedded within N-doped carbon nanosheets (Cu/CuO@NC-900) are successfully synthesized by combining a facile hydrothermal route with a solid calcination technique. Benefitting from the electronic interaction between Cu and CuO, the generated abundant highly active Cu-N-x active sites and the high conductivity of the N-doped carbon nanosheets, the resulting Cu/CuO@NC-900 material shows superior ORR performance in alkaline media, exhibiting a high half-wave potential of similar to 0.868 V, and a robust stability and methanol tolerance, even outperforming commercial 20 wt% Pt/C. Our study opens up a new avenue for the rational design and fabrication of efficient and durable noble-metal-free Cu-based electrocatalysts for energy conversion and storage.