Visible-light-driven photocatalysis: S-scheme CuFe2O4/AgIn5S8 Hybrids for efficient doxycycline hydrochloride degradation

AgIn 5 S 8 and CuFe 2 O 4 (CFO) were first prepared separately via hydrothermal synthesis and a two-step calcination method (using an ethylene glycol-metal complex precursor), respectively. The S-scheme CFO/AgIn 5 S 8 heterojunction was then formed by electrostatic assembly of CFO onto AgIn 5 S 8 . Their photocatalytic performance in degrading doxycycline hydrochloride (DOX) under visible-light irradiation was systematically investigated. Comprehensive characterization techniques were employed to examine the structural features, morphological characteristics, optical properties, and magnetic behavior of the synthesized materials. Results demonstrate that incorporating an optimal amount of CFO substantially enhances three critical properties of AgIn 5 S 8 : (i) visible-light absorption capacity, (ii) separation efficiency of photogenerated charge carriers, and (iii) cycling stability. The 15%CFO/AgIn 5 S 8 composite exhibited outstanding photocatalytic activity, achieving 85% DOX degradation with a reaction rate constant (0.00726 min −1 ) that was 5.76-fold higher than that of pristine AgIn 5 S 8 . Radical scavenging experiments revealed that hydroxyl radicals (·OH) and superoxide radicals (·O 2 − ) serve as the predominant active species. This study offers valuable insights for designing efficient, magnetically recoverable photocatalysts for antibiotic degradation under visible-light illumination.