Effect of morphology especially leaf-like morphology on surface Fe2+ content of α-Fe2O3 in photo-assisted fenton-like degradation of organic contaminants

Surface Fe2+ content has become a limiting step of α-Fe2O3 Photo-assisted Fenton catalytic activity, and a high-efficiency process is urgently required to enhance it. Herein, α-Fe2O3 catalysts with three different morphologies (cube, sphere, and leaf-like) were successfully synthesized under hydrothermal conditions and presented quite different Photo-assisted Fenton-like activities for Rhodamine B (RhB) degradation. Unexpectedly, catalysts show certain activity, especially leaf-like α-Fe2O3 (L-Fe2O3) showed the highest RhB catalytic degradation activity. The mechanistic study has found that the morphology will change the surface Fe2+ content of α-Fe2O3, which will affect the Fe2+/Fe3+ cycle and the role of surface Fe2+ in a Photo-assisted Fenton-like system proved by the results of XPS measurements and 2,2-bipyridine (BPY) quenching experiment. In addition, the L-Fe2O3 catalyst represented broad applicability and stability, which is beneficial for the actual industrial application.