Electronic Structure Modulation Via Iron-Incorporated NiO to Boost Urea Oxidation/Oxygen Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Urea-assisted water splitting offers reduced energy consumption for hydrogen production and mitigates urea pollution.
• Heteroatom doping in nickel-based electrocatalysts can tune electronic structures for improved catalytic activity.
• Existing synthesis methods for doped electrocatalysts are often complex, time-consuming, and yield low amounts.

Purpose of the Study:

• To develop a rapid and facile synthesis method for Fe-doped NiO electrocatalysts.
• To investigate the effect of iron doping on the electronic structure and catalytic performance of NiO for urea oxidation.
• To evaluate the performance of Fe-NiO catalysts in urea oxidation reaction (UOR) and a dual electrode urea electrolytic system.

Main Methods:

• Solution combustion synthesis for rapid production of Fe-doped NiO electrocatalysts.
• Characterization of synthesized materials to confirm doping and structural properties.
• Electrochemical testing of Fe-NiO catalysts for UOR and in a urea electrolytic system.

Main Results:

• Successfully synthesized 1.1107 g of Fe-NiO electrocatalysts in 5 minutes using solution combustion.
• Iron incorporation modulated the electronic environment of Ni sites, lowering Gibbs free energy for intermediates and enhancing C-N bond cleavage.
• Fe-NiO catalysts achieved 50 mA cm⁻² at 1.334 V during UOR and operated at 1.43 V at 10 mA cm⁻² in a dual electrode system.

Conclusions:

• The rapid solution combustion method is effective for synthesizing Fe-NiO electrocatalysts.
• Fe-doping significantly enhances the electrocatalytic activity of NiO for UOR by optimizing electronic structure and intermediate binding.
• Fe-NiO catalysts demonstrate promising performance for efficient hydrogen production via urea electrolysis.