Bifunctional zeolitic imidazolate framework-67 coupling with CoNiSe electrocatalyst for efficient hydrazine-assisted...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Oxygen evolution reaction (OER) in water splitting is energy-intensive.
• Hydrazine oxidation reaction (HzOR) offers a promising alternative for energy-saving hydrogen generation.
• Development of efficient electrocatalysts is crucial for HzOR and hydrogen evolution reaction (HER).

Purpose of the Study:

• To investigate zeolitic imidazolate framework-67 coupled with CoNiSe-3 (ZIF67@CoNiSe-3) as a bifunctional electrocatalyst.
• To evaluate the electrocatalytic performance for both HER and HzOR.
• To explore the potential for energy-saving hydrogen production through overall hydrazine splitting.

Main Methods:

• Synthesis of ZIF67@CoNiSe-3 with a nanoflower structure and porous nanosheet arrays.
• Electrochemical characterization of HER and HzOR performance, including overpotential and Tafel slope.
• Testing of the catalyst in a two-electrode cell for overall hydrazine splitting (OHzS) stability.
• First-principles calculations (DFT) to elucidate reaction mechanisms.

Main Results:

• ZIF67@CoNiSe-3 exhibits excellent HER activity with a low overpotential of 49 mV at 10 mA·cm⁻² and a Tafel slope of 41.4 mV·dec⁻¹.
• The catalyst demonstrates superior HzOR performance, achieving 400 mA·cm⁻² at 0.13 V vs RHE with a Tafel slope of 44.3 mV·dec⁻¹.
• For OHzS, ZIF67@CoNiSe-3 requires a low cell voltage of 0.45 V at 100 mA·cm⁻² with 30 hours of stability.

Conclusions:

• ZIF67@CoNiSe-3 is a highly efficient, low-cost bifunctional electrocatalyst for HER and HzOR.
• The developed catalyst enables energy-saving hydrogen production via overall hydrazine splitting.
• This research provides a viable strategy for efficient hydrogen generation using advanced catalytic materials.