Metal-organic framework decorated with black tea-derived activated carbon as electrocatalyst for alkaline-based...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The hydrogen evolution reaction (HER) is crucial for large-scale hydrogen production via water-splitting electrolysis.
• Precious group metal (PGM) catalysts are costly, driving the need for abundant, low-cost alternatives.
• Metal-organic frameworks (MOFs) and activated carbon (AC) are promising materials for catalysis.

Purpose of the Study:

• To investigate the efficacy of a zinc-based metal-organic framework (Zn-MOF) decorated with black tea-derived activated carbon (AC) as a non-PGM electrocatalyst for HER.
• To characterize the structural and electrochemical properties of the synthesized Zn-MOF/AC composite and its precursors.
• To evaluate the synergistic effects between Zn-MOF and AC in enhancing HER performance.

Main Methods:

• Synthesis and characterization of Zn-MOF/AC composite and precursors using SEM, Raman, XRD, FTIR, and TGA.
• Fabrication of screen-printed electrodes with the active materials.
• Electrochemical performance evaluation using CV, LSV, EIS, Tafel measurements, and TOF calculations.

Main Results:

• The Zn-MOF/AC composite exhibited a low overpotential of 0.32 V at 6 mAcm⁻².
• The composite demonstrated a large electrochemically active surface area (ECSA) of 31.81 cm².
• Zn-MOF/AC showed a lower Tafel slope (113.3 mV·dec⁻¹) and a higher TOF (10.14 x 10⁻⁴ mol H₂·s⁻¹) compared to Zn-MOF alone.

Conclusions:

• The Zn-MOF/AC composite presents a highly effective and synergistic electrocatalyst for hydrogen evolution.
• The material offers a promising, cost-effective alternative to PGM catalysts for large-scale hydrogen production.
• The enhanced performance is attributed to abundant active sites and improved charge transfer kinetics.