Surface-Engineered MoO_x/CN Heterostructures Enable Long-Term SF₆ Photodegradation via Suppressed Fluoridation

Area of Science:

• Materials Science
• Environmental Chemistry
• Catalysis

Background:

• Sulfur hexafluoride (SF₆) is a highly stable and potent greenhouse gas, posing significant environmental challenges.
• Current degradation methods face limitations due to the stable structure of SF₆.
• Photocatalysis offers a low-energy degradation pathway, but catalyst deactivation by fluoride deposition is a major obstacle.

Purpose of the Study:

• To develop a novel photocatalyst resistant to fluoride deposition for efficient and long-term degradation of SF₆.
• To investigate the structure-activity relationship of graphitic carbon nitride (CN) loaded with MoO_x (CNM) for SF₆ decomposition.
• To provide a sustainable solution for mitigating the environmental impact of SF₆ emissions.

Main Methods:

• Synthesis of a thin-layer graphitic carbon nitride (CN) material loaded with MoO_x (CNM) via molecular structure design and nanostructure regulation.
• Characterization of the CNM photocatalyst for its surface area, charge carrier mobility, and electron-hole separation efficiency.
• Evaluation of the SF₆ degradation performance and catalytic durability of CNM compared to pristine g-C₃N₄.

Main Results:

• The synthesized CNM exhibits a high specific surface area and enhanced contact between reactants and active sites.
• Efficient electron-hole separation was achieved in CNM due to the formation of Mo-N bonds.
• CNM demonstrated a significantly higher SF₆ degradation efficiency (1.73 mmol/g) compared to pristine g-C₃N₄ (0.21 mmol/g) after one day, with prolonged catalytic durability.

Conclusions:

• The developed MoO_x-loaded graphitic carbon nitride (CNM) is a highly effective and durable photocatalyst for SF₆ degradation.
• CNM offers a promising low-energy, high-efficiency approach to mitigate the environmental impact of SF₆.
• This study provides a new avenue for designing advanced photocatalytic materials for environmental remediation and climate change mitigation.