One-pot synthesis of multifunctional electrocatalyst for hydrogen evolution, oxygen evolution and oxygen reduction

In this work, we report a facile method to prepare P, N co-doped porous carbon (PNPC) by the carbonization of covalent organic polymer (COP) used as efficient metal-free electrocatalyst for hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Overpotential is only 150 mV for the PNPC electrocatalyst to reach 10 mA cm(-2)in the acidic medium due to the heteroatom dopants in the carbon matrix; meanwhile, stable HER activity is recorded during 5000 potential cycles. Additionally, overpotential is 343 mV for PNPC electrocatalyst to drive OER catalysis with 10 mA cm(-2), which is comparable to the benchmarked IrO2(320 mV). Similarly, PNPC electrocatalyst can achieve a Pt-like ORR catalytic activity. The power density of the assembled rechargeable zinc-air battery (ZAB) is 1.8 times higher than that of the commercial system (Pt/C-IrO2) and charge-discharge voltage gap is well maintained during 20 h test, implying the high stability of the formed PNPC electrocatalyst.