Electropolymerization Fabrication of Co Phosphate Nanoparticles Encapsulated in N,P-Codoped Mesoporous Carbon Networks as a 3D Integrated Electrode for Full Water Splitting

The development of high-performance nonprecious electrocatalysts toward both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is of great significance for overall water splitting but remains a grand challenge. In this study, Co phosphate (CP) nanoparticles encapsulated in three-dimensional porous N,P-codoped carbon networks (NPC) were fabricated by direct growth on carbon cloth (CC), which were further used as an integrated three-dimensional (3D) electrode for cost-effective and energy efficient HER and OER both in acid and alkaline medium. Impressively, the as-obtained flexible integrated electrode exhibited excellent activities and robust stability, due to the unique 3D architecture with improved electron transport capability, high number of active sites, and channels for reactant/product transfer. Our experimental results show significantly enhanced performance for such engineered nanostructures due to the synergistic effect from nanoparticles encapsulation and nitrogen and phosphorus doping on carbon structures. Such an versatile electrode can serve as a bifunctional catalyst for overall water splitting with excellent catalytic performance and durability in a more direct and simple way, which reduces the production cost of practical technological devices. The new design demonstrated here opened avenues for simple, low-cost, and scalable manufacture of high performance bifunctional catalysts for renewable energy technologies.