Synergistic doping and structural engineering over dendritic NiMoCu electrocatalyst enabling highly efficient...

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• High-efficiency hydrogen generation is crucial for renewable energy.
• Developing non-precious metal electrocatalysts is a key objective.
• Electrocatalysts need to be active for both hydrogen evolution and urea oxidation reactions for efficient overall water/urea electrolysis.

Purpose of the Study:

• To fabricate a novel trimetallic electrocatalyst with a dendritic nanostructure for enhanced hydrogen evolution reaction (HER) and urea oxidation reaction (UOR).
• To investigate the electrocatalytic performance of the NiMoCu-NF catalyst for hydrogen generation and urea oxidation.
• To elucidate the mechanism behind the enhanced catalytic activity.

Main Methods:

• Gas-template electrodeposition strategy to fabricate NiMoCu-NF on nickel foam.
• Electrochemical characterization to evaluate HER and UOR activity (overpotential, voltage).
• Combined experimental and simulation analysis to understand the catalytic mechanism and nanostructure effects.

Main Results:

• The NiMoCu-NF catalyst exhibited superior HER activity with an overpotential of 52 mV at 10 mA cm⁻².
• The derived nickel-based (oxy)hydroxide species showed efficient UOR performance, achieving overall electrolysis at 1.54 V and 50 mA cm⁻².
• The 3D nanostructure induced a 'Gas Microfluidic Pumping' (GMP) effect, improving mass transfer and reaction kinetics.

Conclusions:

• The NiMoCu-NF catalyst demonstrates excellent bifunctional electrocatalytic activity for HER and UOR.
• The dendritic nanostructure and GMP effect are critical for enhancing electrocatalytic performance.
• This work provides a promising pathway for developing efficient non-precious metal electrocatalysts for hydrogen production.