PH-controlled MnFe2O4@ SnS2 nanocomposites for the visible-light photo-Fenton degradation

Abstract The magnetically separable MnFe2O4 nanoparticles (15–50 nm) are synthesized onto SnS2 microflowers (diameter 1–1.5 μm, thickness 50 nm), fabricating a direct Z-scheme MnFe2O4@SnS2 heterojunction nanocomposite via two-step hydrothermal. The MnFe2O4@SnS2 composites with an appropriate SnS2 content exhibit enhanced photo-Fenton degradation performances to make efficient separation of photoexcited electron/hole pairs. In the photo-Fenton degradation tests, MnFe2O4@SnS2-2 shows excellent performance that 92.08 % of methylene blue (MB) could be photocatalyzed within120 min with pH = 9 and 1.5 mL H2O2, which is about 2.43 times than that of bare MnFe2O4 nanoparticles. In general, the Mn2+ and Fe2+ in-situ regenerated through accepting electrons from the cathode as the result of the Z-scheme electron transfer. Moreover, over 88 % of MB is still removed in the 5th run is attributed that SnS2 driven also extend the longevity of the MnFe2O4 catalyst. Different capture agents IPA, BQ and TEOA investigation displays that ·OH is the main active specie.