CoP/CoN heterostructural active centers supported on nitrogen carbon nanorod arrays as freestanding high-performance trifunctional electrocatalysts

Developing high-activity and long-term durable trifunctional electrocatalysts for the oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is of crucial significance and demanding. In this work, a CoP/CoN heterostructural active center supported by nitrogen carbon nanorod arrays on carbon cloth catalyst (CoP/CoN@NCNRs/CC) is reported and acts as a self-supported electrode for zinc-air batteries and water splitting. Both density functional theory calculation (DFT) and experimental results reveal that the favourable catalytic performance is due to the highly dispersed active sites where Co-Nx-C with ORR and OER activity and CoP with OER and HER activity exhibited a synergistic role. Furthermore, the NCNRs can protect the active sites from corrosion and participate in the ORR. CoP/CoN@NCNRs/CC as an air electrode for liquid zinc-air batteries possesses a great power density and energy density and shows superior stability with a long operating life of more than 420 h at 10 mA cm-2. The all-solid-state Zn-air batteries and water splitting device are self-assembled and both of them have potential for application in flexible electronics and new energy devices. Freestanding CoP/CoN heterostructure electrocatalysts for zinc-air batteries and water splitting, and the catalytic mechanism was verified based on DFT and experiments.