Mononuclear Fe(III) Schiff base antipyrine complexes for catalytic hydrogen generation

Area of Science:

• Inorganic Chemistry
• Catalysis
• Materials Science

Background:

• Mononuclear iron(III) complexes are crucial in catalysis.
• Schiff base ligands offer versatile coordination environments.
• Hydrogen evolution reaction (HER) is a key process for sustainable energy.

Purpose of the Study:

• To synthesize and characterize novel mononuclear Fe(III) complexes with antipyrine Schiff base ligands.
• To evaluate the electrocatalytic and photocatalytic activity of these complexes for hydrogen production.
• To assess the stability and performance of the catalysts in varying environmental conditions.

Main Methods:

• Synthesis and full characterization of Fe(III) complexes.
• Electrochemical studies including cyclic voltammetry and chronoamperometry.
• Photocatalytic experiments using a chromophore and sacrificial donor.
• Catalyst performance evaluation in natural water samples.

Main Results:

• Complexes exhibit a planar tetradentate coordination geometry.
• Electrocatalytic hydrogen evolution occurs at -1.4 V vs. Fc+/Fc with 700 mV overpotential and a turnover frequency of 700 s⁻¹.
• Photocatalytic activity demonstrated >1700 turnovers over 40 hours with a quantum yield up to 5.4%.
• Catalysts maintain activity in natural water samples with diverse salinity.

Conclusions:

• The synthesized Fe(III) complexes are effective electrocatalysts and photocatalysts for hydrogen evolution.
• These complexes show potential for application in sustainable hydrogen production technologies.
• The catalysts' robustness in natural water environments highlights their practical applicability.