Coupled nanocomposite Co5.47N-Co3Fe7 inlaid in tremella-like carbon framework as highly efficient multifunctional electrocatalyst for oxygen transformation and overall water splitting
Electrocatalysts with high activity, low cost and long-term durability for the oxygen transformation and water splitting are highly demanded for realizing large-scale commercial application of the renewable energy technologies, such as metal-air batteries and water splitting cells, but remain as a great challenge. Herein, the graphene/nanotube-constructed tremella-like carbon framework with 3D open aisles embedding the coupled Co5.47N and Co3Fe7 nanoparticles (Co5.47N@Co3Fe7/N-Cs) were created by hydrothermal-pyrolysis strategy. The mutual entanglement and connection of the nanosheets and nanotubes builds the carbon network with hierarchically porous structure and multifarious active centers such as Fe-Co, Co(Fe)-Nx moieties and nitrogen-doped carbon (N-C) co-existed on the surface of the prepared Co5.47N@Co3Fe7/N-Cs, which exhibits excellent trifunctional electrocatalytic performance for the ORR, OER and HER. The primary zinc-air battery assembled with Co5.47N@Co3Fe7/N-C-900 gain an advantage over the Pt/C-based counterparts. Besides, the performance of overall water splitting device using Co5.47N@Co3Fe7/N-C-900 as electrode materials is comparable to that of Pt/C-IrO2 pair-assembled cell. To the best of our knowledge, this is the top-notch trifunctional electrocatalysts for ORR, HER and OER so far. This work provides an effective strategy to prepare high-performance trifunctional electrocatalysts with the excellent catalytic performance and wide application prospect in the sustainable energy conversion techniques.