Dendrimer-Ni-Based Material: Toward an Efficient Ni-Fe Layered Double Hydroxide for Oxygen-Evolution Reaction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Nickel-iron oxides are common catalysts for water splitting.
• Developing efficient catalysts for the oxygen-evolution reaction (OER) is crucial for water splitting technologies.

Purpose of the Study:

• To develop a new synthesis method for Ni-Fe layered double hydroxides (Ni-Fe LDHs) using dendrimers for enhanced OER performance.
• To investigate the catalytic activity of the synthesized Ni-Fe LDHs for OER.

Main Methods:

• Synthesis of a Ni-Fe LDH precatalyst using a generation 3.5 dendrimer with carboxylate surface groups and Ni(II) ions.
• Electrochemical characterization of the catalyst for OER using various electrodes (FTO, Au, Pt, Ni foam, glassy carbon).
• Material characterization using multiple analytical techniques.

Main Results:

• The dendrimer facilitated the formation of highly dispersed Ni-Fe LDHs with increased active sites.
• The catalyst achieved a current density of 100 mA/cm² on Ni foam with a low overpotential of 297 mV and a Tafel slope of 60.8 mV/decade.
• On Au and Pt electrodes, current densities of 50 mA/cm² were achieved with overpotentials of 333 mV and 317 mV, respectively, exhibiting low Tafel slopes.

Conclusions:

• Dendrimer-templated synthesis is an effective strategy for creating high-performance Ni-Fe LDH catalysts for OER.
• The synthesized Ni-Fe LDH catalyst shows excellent activity and efficiency for the oxygen-evolution reaction, especially on Ni foam.