Selective hydroxyl generation for efficient pollutant degradation by electronic structure modulation at Fe sites.

Area of Science:

• Materials Science
• Environmental Chemistry
• Catalysis

Background:

• Hydrogen peroxide (H2O2) is a key green oxidant for sewage treatment.
• Improving H2O2 activation and radical generation is crucial for efficient pollutant degradation.
• Developing advanced catalysts for visible-light-driven oxidation is an active research area.

Purpose of the Study:

• To synthesize and evaluate a Cu-doped α-Fe2O3 catalyst for enhanced H2O2 activation under visible light.
• To investigate the mechanism of H2O2 activation and radical generation by the catalyst.
• To assess the catalyst's efficiency in degrading organic pollutants in wastewater.

Main Methods:

• Synthesis of Cu-doped α-Fe2O3 (7% Cu-Fe2O3) catalyst.
• Characterization of catalyst properties, including electronic structure and light absorption.
• Evaluation of catalytic activity for H2O2 activation and organic pollutant degradation under visible light.
• Mechanistic studies on H2O2 cleavage pathways and radical generation.

Main Results:

• Cu doping shifted the Fe d-band center, enhancing H2O2 adsorption and activation.
• The H2O2 cleavage pathway shifted to homolytic cleavage, favoring •OH generation.
• Cu doping improved light absorption and charge carrier separation in α-Fe2O3.
• 7% Cu-Fe2O3 showed 3.6 times higher ciprofloxacin degradation rate compared to undoped α-Fe2O3.
• The catalyst demonstrated broad efficiency for various organic pollutants.

Conclusions:

• Cu-doped α-Fe2O3 is an effective catalyst for visible-light-driven H2O2 activation.
• The catalyst enhances •OH radical generation selectivity and photocatalytic activity.
• This approach offers a promising solution for efficient degradation of organic pollutants in sewage treatment.