Fabricating Fe3O4-schwertmannite as a Z-scheme photocatalyst with excellent photocatalysis-Fenton reaction and recyclability

Here we reported an effective method to solve the rate-limiting steps, such as the reduction of Fe 3+ to Fe 2+ and an invalid decomposition of H 2 O 2 in a conventional Fenton-like reaction. A magnetic heterogeneous photocatalyst, Fe 3 O 4 -schwertmannite (Fe 3 O 4 -sch) was successfully developed by adding Fe 3 O 4 in the formation process of schwertmannite . Fe 3 O 4 -sch shows excellent electrons transfer ability and high utilization efficiency of H 2 O 2 (98.5%). The catalytic activity of Fe 3 O 4 -sch was studied through the degradation of phenol in the heterogeneous photo-Fenton process. Phenol degradation at a wide pH (3 - 9) was up to 98% within 6 min under visible light illumination with the Fe 3 O 4 -sch as heterogeneous Fenton catalyst, which was higher than that using pure schwertmannite or Fe 3 O 4 . The excellent photocatalytic performance of Fe 3 O 4 -sch is ascribed to the effective recycling between Fe 3+ and Fe 2+ by the photo-generated electron, and also profit from the formation of the “Z-Scheme” system. According to the relevant data, photocatalytic mechanism of Fe 3 O 4 -sch for degrading phenol was proposed. This study not only provides an efficient way of enhancing heterogeneous Fenton reaction , but also gives potential application for iron oxyhydroxysulfate mineral.