Facile controlled formation of CoNi alloy and CoO embedded in N-doped carbon as advanced electrocatalysts for oxygen evolution and zinc-air battery

Constructing Schottky barrier of alloy/metal oxide interfaces is an emerging approach to design electrocatalysts with desired performance. Herein, a nitrogenous organic modified bimetal layered hydroxide salts (LHS) precursor is used to prepare CoNi alloy and CoO coupled nitrogen-doped carbon (NC) hybrids on carbon paper (CP) via a one-step pyrolysis at only 500 degrees C. Through adjusting the metal molar ratio in LHS precursor and the pyrolysis temperature, CoO is in situ produced during pyrolysis. Since both alloy and metal oxide possess potential oxygen evolution reaction activity, the resulting CoNi-CoO@NC/CP exhibits enriched electrochemical active surface area, small overpotential (309 mV) at current density of 10 mA cm(-2), low Tafel slope (67.7 mV dec(-1)), and good durability for 64 h at similar to 20 mA cm(-2) in 1.0 M KOH. Furthermore, a zinc-air battery based on this catalyst shows a high specific power of 96.2 W g(cat)(-1), which exceeds that of conventional RuO2+Pt/C catalyst (66.8 W g(cat)(-1)). This work provides an appealing approach for the development of highly efficient alloy/metal oxide electrocatalysts for rechargeable metal-air battery. (C) 2021 Elsevier Ltd. All rights reserved.