Asymmetrical Sc coordination-induced bridging structure and surface relaxation for boosting H2O2 photoactivation in Fenton-like catalysis

Abstract

The utilization of photo-Fenton technology in the treatment of refractory pollutants is a significant area, dependent on a stable and highly efficient catalyst for reliable performance. However, the weak van der Waals force between two semiconductors, such as graphitic carbon nitride (g-C₃N₄) and MoSe₂, limits charge carrier transfer and photocatalytic activity. Herein, a single-atom of the transition metal scandium (Sc) is introduced into the g-C₃N₄/MoSe₂ (CSM) heterojunction interfaces to form a single-atom bridging structure (Se–Sc–N) for H₂O₂ activation in a photo-Fenton-like system. The Sc single-atom bridging structure improves the interaction between the two semiconductors, and the asymmetrical coordination causes surface relaxation to lower the activation energy barrier of H₂O₂ to ˙OH. Theoretical calculations and experimental characterization demonstrate that the unique structure precisely boosts interfacial charge transfer in g-C₃N₄/MoSe₂ heterojunctions. The synthesized CSM achieves 100% removal of tetrabromobisphenol A (TBBPA) within 20 min, with a debromination efficiency of 54% (120 min) under visible light irradiation. These findings enrich the application of single-atom catalysts in advanced oxidation fields and reveal the bridging function of single-atoms between semiconductors in photo-Fenton-like system.