Crystal Plane Regulation Promotes the Oriented Conversion of Radicals in Heterogeneous Persulfate Catalyzed Oxidation
Zhenchun Tang1, Xinquan Zhou1, Mengyao Du1
1School of Chemistry and Chemical Engineering, Henan University of Science and Technology, Luoyang, 471000, China.
Small (Weinheim an Der Bergstrasse, Germany)
|February 27, 2024
Summary
High crystallinity nano-Co3O4 catalysts with exposed (111) planes significantly boost the degradation of pollutants by enhancing reactive oxygen species (ROS) formation. This crystal plane effect is key for efficient persulfate oxidation systems.
Area of Science:
- Materials Science
- Catalysis
- Environmental Chemistry
Background:
- The mechanism of crystal plane effects in heterogeneous persulfate oxidation of reactive oxygen species (ROS) is not fully understood.
- Understanding these effects is crucial for designing efficient catalysts for pollutant degradation.
Purpose of the Study:
- To investigate the influence of nano-Co3O4 catalyst crystallinity and exposed crystal planes on persulfate-activated oxidation.
- To elucidate the role of crystal planes in the selective conversion of ROS for pollutant degradation.
Main Methods:
- Hydrothermal synthesis of nano-Co3O4 catalysts with controlled crystallinity and (111) plane exposure.
- Degradation experiments using p-nitrobenzaldehyde (4-NBA) as a model pollutant.
- Radical quenching, EPR, XPS, and DFT calculations to analyze reaction mechanisms and active sites.
Main Results:
- High crystallinity Co3O4 catalysts with dominant (111) planes showed 100% 4-NBA degradation, outperforming low crystallinity catalysts (74.5%).
- Increased (111) plane exposure significantly enhanced sulfate radical (SO4•−) and hydroxyl radical (•OH) yields.
- Oxygen vacancies (Ov) on the (111) planes were identified as key active sites facilitating PMS adsorption and electron transfer.
Conclusions:
- The (111) crystal plane of Co3O4 plays a critical role in enhancing ROS generation and catalytic activity in persulfate oxidation.
- Oxygen vacancies on the (111) plane are crucial for efficient persulfate activation and radical formation.
- This study offers a strategy for designing advanced catalysts for efficient pollutant degradation via persulfate systems.
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