Bimetal nanoparticles hybridized with carbon nanotube boosting bifunctional oxygen electrocatalytic performance

Developing bifunctional oxygen catalysts with high efficiency and low cost to replace platinum-group metal catalysts commonly utilized in metal-air batteries is critically desired. In this article, a convenient method to synthesis NiFe nanoparticles hybridized with N-doped carbon nanotube (NiFe@N-CNTs) is reported. Electrocatalytic performance analysis indicates that Ni_xFe_1−x@N-CNTs offers favorable oxygen reduction reaction (ORR) kinetics (onset potential (E_onset) is 0.87 V and half-wave potential (E_1/2) is 0.84 V), together with excellent oxygen evolution reaction (OER) performance (an overpotential of 270 mV to drive 10 mA·cm⁻²). Contributed by the synergetic effect between NiFe alloy and N-CNTs, when being utilized as air cathode, rechargeable Zn-air batteries present superior cycling stability for over 150 h. This research provides a universal strategy to synthesize the hybrids of intertwined carbon nanotube matrix loaded with alloy nanoparticles. Graphical abstract: [Figure not available: see fulltext.]