Ultrafine CoPt3 nanoparticles encapsulated in nitrogen-doped carbon nanospheres for efficient water electrolysis

Rational design of nanostructures with excellent activity and stability for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) to realize efficient hydrogen production is essential for renewable energy development and conversion. Here, we have designed a special pyrolysis reduction method for the synthesis of CoPt3 nanoparticles (NPs) embedded in N-doped carbon nanospheres (CoPt3@NC). In this process, a facile impregnation combined with pyrolysis reduction strategy is carried out to produce well-dispersed CoPt3 nanoparticles within the N-doped carbon, and the resulting CoPt3@NC nanospheres with trace Pt content exhibit superior HER and OER activity to pure Pt@NC, which needs an ultralow overpotential of 65 mV and 360 mV to drive 10 mA/cm(2) in 1.0 M KOH, respectively, and also with excellent long-term durability. The excellent HER and OER activities of CoPt3@NC nanospheres are mainly ascribed to the high surface area, N-doping, and synergistic effect between catalyst and carrier. This work provides a feasible strategy to design carbon-based heterostructures with high catalytic activity and stable properties.