Figure 5. Photo-Fenton tests.

Cycle test for the solar-driven degradation of methyl-orange (black line: CoFe₂O₄/GAs with H₂O₂ under irradiation; red line: CoFe₂O₄/GAs with H₂O₂ in the dark; blue line: CoFe₂O₄/GAs without H₂O₂ in the dark; dark cyan line: pure CoFe₂O₄ powders with H₂O₂ under irradiation) (70 mL MO, 10 mg/L) under simulated solar light irradiation (with an AM 1.5 air mass filter) (150 mM H₂O₂ (30 wt%), the initial pH was 3.5) (a). Effect of solution pH on photodegradation efficiency of MO on CoFe₂O₄/GAs photocatalyst (70 mL MO, 10 mg/L; 150 mM H₂O₂ (30 wt%); t:30 min; the third cycle data) (b). Effect of H₂O₂ concentration on photodegradation efficiency of MO on CoFe₂O₄/GAs photocatalyst (70 mL MO, 10 mg/L; pH: 3.5; the third cycle data) (c). Photo-Fenton reaction mechanism of CoFe₂O₄/GAs (d).