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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. [ABSTRACT FROM AUTHOR]

Constructing high-performance catalyst for hydrogen evolution reaction (HER) is the effective way to eliminate energy crisis. Reasonable engineering of heterointerfaces can effectively create more active sites and promote electron transfer resulting in improvement in the catalytic activity. In this work, we synthesize the well-defined molybdenum carbides and tungsten carbides nano-heterostructure (Mo 2 C/W 2 C) by carbonization with CH 4 /H 2 at 800 °C showing excellent HER activity, fast kinetics and electrochemical stability in both alkaline and acidic electrolytes. Mo 2 C/W 2 C requires only 140 and 132 mV overpotentials to reach catalytic current density of 10 mA cm−2 in 0.5 M H 2 SO 4 and 1 M KOH electrolyte, respectively. Tafel slope is as low as 51 and 76 mV dec−1 in 0.5 M H 2 SO 4 and 1 M KOH comparable to the benchmarked Pt/C. Moreover, Mo 2 C/W 2 C exhibits a superior stability with slight deterioration in HER performance after 5000 potential cycles. This work elucidates that the rational construction of heterointerfaces is favorable for design of efficient non-noble metal electrocatalyst for HER catalysis. Image 1 • Mo 2 C/W 2 C heterogeneous electrocatalyst is successfully synthesized. • The overpotential is 140 mV for Mo 2 C/W 2 C to deliver 10 mA cm−2 in acidic medium. • Mo 2 C/W 2 C requires 132 mV overpotential to reach 10 mA cm−2 in alkaline medium. [ABSTRACT FROM AUTHOR]