Boosted photocatalytic removal of Cr(VI) using MoS2 modified g-C3N4/ZnFe2O4 magnetic heterojunction composites

Photocatalysts can be effectively recovered and reused by compounding with magnetic nanostructures. How to further improve the photocatalytic performance of magnetic heterojunction photocatalysts remains a great challenge. In this work, g-C3N4/ZnFe2O4 (CN/ZFO) magnetic heterojunction photocatalyst was first prepared and then modified with ultrathin MoS2 (CN/ZFO/MoS2) by simple ball-milling method. Then the photocatalytic removal of Cr(Ⅵ) performance of the prepared series photocatalysts was evaluated in detail. The optimum CN/ZFO/MoS2 can achieve 99.3% Cr(Ⅵ) removal under 200-min simulated sunlight illumination, which is much higher than CN/ZFO (54.0%). The enhanced photocatalytic performance benefits from the modification of MoS2, which improves the light absorption performance, facilitates the transfer of photogenerated carriers, increases the concentration of photogenerated carriers and promotes the effective separation of photogenerated carriers. This work provides a theoretical basis for further preparation of magnetic recyclable photocatalysts with high photocatalytic performance.