Login / Signup

Synergetic Nanostructure Engineering and Electronic Modulation of a 3D Hollow Heterostructured NiCo 2 O 4 @NiFe-LDH Self-Supporting Electrode for Rechargeable Zn-Air Batteries.

Zunpeng HuSenjie DongQuanfeng HeZihao ChenDing Yuan
Published in: Inorganic chemistry (2023)
Developing electrocatalysts that integrate the merits of the hollow structure and heterojunction is an attractive but still challenging strategy for addressing the sluggish kinetics of oxygen evolution reaction (OER) in many renewable energy technologies. Herein, a 3D hierarchically flexible self-supporting electrode with a hollow heterostructure is intentionally constructed by assembling thin NiFe layered double hydroxide (LDH) nanosheets on the surface of metal-organic framework-derived hollow NiCo 2 O 4 nanoflake arrays (NiCo 2 O 4 @NiFe-LDH) for rechargeable Zn-air batteries (ZABs). Theoretical calculations demonstrate that the interfacial electron transfer from NiFe-LDH to NiCo 2 O 4 induces the electronic modulation, improves the conductivity, and lowers the reaction energy barriers during OER, ensuring high catalytic activity. Meanwhile, the 3D hierarchically hollow nanoarray architecture can afford plentiful catalytic active sites and short mass-/charge-transfer pathways. As a result, the obtained catalyst exhibits remarkable OER electrocatalytic performance, showing low overpotentials (only 231 mV at 10 mA cm -2 , 300 mV at 50 mA cm -2 ) and robust stability. When assembling liquid and flexible solid-state ZABs with NiCo 2 O 4 @NiFe-LDH as the OER catalyst, the ZABs achieve excellent power density, high specific capacity, superior cycle durability, and good bending flexibility, exceeding the RuO 2 + Pt/C benchmarks and other previously reported self-supporting catalysts. This work not only constructs an advanced hollow heterostructured catalyst for sustainable energy systems and wearable electronic devices but also provides insights into the role of interfacial electron modulation in catalytic performance enhancement.
Keyphrases