Metallophthalocyanine-Based Polymer-Derived Co<sub>2</sub>P Nanoparticles Anchoring on Doped Graphene as High-Efficient Trifunctional Electrocatalyst for Zn-Air Batteries and Water Splitting
Qi Shao, Yan Li, Xu Cui, Tianjiao Li, Heng‐guo Wang, Yanhui Li, Qian Duan, Zhenjun Si
Abstract
Covalent organic polymers (COPs) provide an interesting platform for constructing the low-cost and highly efficient multifunctional electrocatalysts in view of their tailorable structures and properties. Herein, Co-phthalocyanine-based COPs (CoPc-COPs) are constructed using cobalt tetraaminophthalocyanine (CoPc(NH2)4) as the organic building unit and phosphonitrilic chloride trimer (Cl6N3P3) as the linker group, which serve as the self-carrier enriched with Co, P, N, and C to derive Co2P nanoparticles anchored on the N, P codoped graphene after carbonization treatment. Benefiting from the unique construction and the metallic property confirmed by density functional theory (DFT) calculations, the Co2P/NPG displays high-efficient trifunctional electrocatalytic performance toward oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER), including excellent oxygen electrocatalytic activity (overpotential of 0.32 V at 10 mA cm–2 for OER, half-wave potential of 0.81 V for ORR) and outstanding stability (98% over 12 h for OER, 89% over 17 h for ORR). Impressively, rechargeable Zn-air batteries (ZABs) that employed Co2P/NPG as the cathode electro-catalyst display a peak power of up to 103.5 mW cm–2 along with a good cycle stability after 55 h. Moreover, the constructed ZABs can be used to power the overall water splitting. Therefore, function-oriented design of metallophthalocyanine-based COPs provides new ways to strategically construct multifunctional electrocatalysts for the wider integrated green energy system.