Facet-dependent nonradical Fenton-like catalysis over Cu₂WS₄: Selective H₂O₂ activation and Cu(III) formation

Area of Science:

• Materials Science
• Environmental Chemistry
• Catalysis

Background:

• Ternary transition metal chalcogenides are vital for heterogeneous Fenton-like catalysts.
• Understanding facet-dependent mechanisms in Cu2WS4 is crucial for optimizing catalytic activity.

Purpose of the Study:

• To synthesize facet-controlled Cu2WS4 catalysts using a one-pot solvothermal method.
• To elucidate the structure-activity relationship of Cu2WS4 in H2O2 activation for pollutant degradation.
• To investigate the facet-dependent mechanism of Cu2WS4 in Fenton-like reactions.

Main Methods:

• One-pot solvothermal synthesis of facet-controlled Cu2WS4.
• Evaluation of catalytic performance for tetracycline (TC) degradation.
• Experimental analysis and theoretical calculations to understand reaction mechanisms.
• Stability tests and toxicity assessments.

Main Results:

• Cu2WS4 dominated by the {101} facet (L-Cu2WS4) exhibited superior TC degradation rates compared to the {001} facet (S-Cu2WS4) and Fe2+/H2O2.
• The {101} facet showed stronger adsorption affinity and lower H2O2 activation energy, promoting non-radical pathways via Cu(III).
• The {001} facet adsorbed O2, inhibiting H2O2 utilization and reducing catalytic activity.
• The L-Cu2WS4/H2O2 system demonstrated wide pH applicability, excellent stability, and effectiveness in complex water bodies.

Conclusions:

• The {101} facet of Cu2WS4 is key for efficient H2O2 activation and TC degradation in Fenton-like reactions.
• Facet engineering provides a strategy for designing high-performance copper-based catalysts for water purification.
• This study deepens the understanding of facet-dependent mechanisms in heterogeneous catalysis for environmental remediation.