Electrodeposition of defect-rich high entropy ZIF and its application in water oxidation

Abstract

High-entropy materials has achieved much attention in the recent decade years. However, there is few reports on high-entropy MOFs due to the large difference of coordination ability for different metal ions. In this work, high-entropy ZIFs are successfully electrodeposited on the nickel foam substrate under high overpotential, and the effects of potential, electrodeposition time and metal precursor concentration on the morphologies and catalytic activity of deposits are examined. The results indicate that the prepared HE-ZIF is made of nanoparticles with a low crystalline structure, and it shows a high electrocatalytic activities for oxygen evolution reaction (OER) as it possesses an abundance of defects such as vacancy defects, lattice distortions and amorphous structure. The overpotential at the current density of 100 mA cm−2 is 290 mV with good durability in 100 h continuous test for OER in 1 mol L−1 KOH.