Nanomaterials - 03

Abstract

The development of efficient and durable bifunctional electrocatalysts for oxygen reduction and evolution reactions (ORR/OER) is crucial for building next-generation energy conversion and storage systems. Here, we report a novel strategy to grow hollow-structured Fe-doped CoNi layered double hydroxide (LDH) shells on highly conductive Ag nanowires (NWs) cores, denoted as CoNiFe LDH@Ag NWs. This is accomplished by using ZIF-67 grown on Ag NWs (ZIF-67@Ag NWs) as the cobalt source and sacrificing template, followed by in situ coprecipitation of multimetal cations (Ni, Fe, etc.). The hollow CoNiFe LDH nanocages formed on Ag NWs can fully expose their active sites by enhancing the specific surface area[1]. Moreover, the high electrical conductivity of Ag NWs ensures an adequate electron transport during the electrocatalytic process[2]. The 3D hierarchical CoNiFe LDH@Ag NWs hybrids demonstrated outstanding performance, showing an overpotential of 225 mV at 10 mA cm-2 for OER, along with an onset potential of 0.92 V and a half-wave potential of 0.82 V for ORR. As a result, as-synthesized CoNiFe LDH@Ag NWs bifunctional electrocatalyst can serve as a promising air electrode for rechargeable Zn−air batteries.