Construction of Partially Amorphous CoNi-LDH for Efficient Water Oxidation

Area of Science:

• Electrochemistry
• Materials Science
• Environmental Chemistry

Background:

• Conventional electrochemical advanced oxidation processes (EAOPs) face challenges like parasitic oxygen evolution and potential halogenated byproduct formation.
• An efficient anodic oxygen evolution reaction (OER) is crucial for coupling with cathodic molecular oxygen activation (MOA) in advanced EAOPs.
• Hysteretic OER is key for generating the necessary anodic O2 supply for integrated OER/MOA processes.

Purpose of the Study:

• To construct novel crystalline-amorphous cobalt-nickel-layered double hydroxide (CoNi-LDH) nanosheets as efficient OER catalysts.
• To investigate the catalytic activity and electrochemical stability of the synthesized CoNi-LDH heterojunction.
• To explore the potential application of this catalyst in the OER/MOA process for improved EAOPs.

Main Methods:

• Synthesized crystalline-amorphous CoNi-LDH nanosheets using a facile one-step ultrasound treatment.
• Evaluated the electrocatalytic performance for OER, including overpotential and current density measurements.
• Assessed the electrochemical stability of the CoNi-LDH catalyst in basic media.

Main Results:

• The CoNi-LDH heterojunction exhibited a low overpotential of 260 mV to achieve a current density of 10 mA cm⁻².
• The catalyst demonstrated excellent electrochemical stability in basic media, outperforming monometallic hydroxide counterparts.
• The partially amorphous and porous structure of the CoNi-LDH nanosheets contributed to its enhanced catalytic activity.

Conclusions:

• Combining crystalline and amorphous phases in CoNi-LDH heterojunctions effectively optimizes OER electrocatalyst activity.
• The developed CoNi-LDH nanosheets show significant promise for application in integrated OER/MOA processes.
• This approach offers a new strategy for designing high-performance OER electrocatalysts for advanced oxidation applications.