Electrodeposited thermally activated amorphous MOFs for efficient water oxidation

Amorphous metal-organic frameworks (MOF) have great advantages in electrocatalysis due to their abundant defective sites and good structural flexibility, while retaining the compositional benefits of their crystalline counterparts. However, their synthesis typically relies on post-treatments of crystalline MOFs and often yields powdery products that require additional polymer binders for electrode fabrication. In this work, a free-standing amorphous MOF-nickel foam (NF) electrode for oxygen evolution reaction (OER) is fabricated through cathodic deposition and thermal treatment. Cathodic deposition allows direct anchoring of amorphous ZIF-62 on NF, while thermal treatment introduces coordination distortion in the ZIF-62 framework, facilitating electron delocalization and reducing charge transfer resistance. The optimized electrode demonstrates remarkable OER performance, delivering a low overpotential of 201 mV at 10 mA cm−2, along with excellent long-term stability for 200 h, surpassing many previously reported crystalline and amorphous MOF-based electrocatalysts. This facile synthetic approach offers a promising opportunity for the design of advanced materials for electrocatalytic devices.