Supramolecular precursor derived loofah sponge-like Fe2Ox/C for effective synergistic reaction of Fenton and photocatalysis

Fenton or photocatalytic degradations of organic contaminants are recognized as promising approaches to address the increasing environmental pollution issues. Herein, we develop the effective synergistic catalysis reaction of Fenton and photocatalysis based on a loofah sponge-like Fe2Ox/C nanocomposite, which exhibits excellent nitrobenzene photocatalytic degradation property. It is noted that Fe2O3 nanoparticles with surface Fe2+ species were encapsulated with an ultrathin carbon layer (denoted as Fe2Ox/C) via a supramolecular self-sacrificing template and following thermal treatment process. The experimental results indicated that the thin layer carbon coating not only inhibited the Fe iron leaching from the Fe2Ox but also prompted the separation and transferring of electrons-hole pairs. The introduction of Fe2Ox/C enables the Fenton reaction to induce a rapid Fe2+/Fe3+ cycle, and meanwhile, together with the photocatalytic reaction to produce continuous active substances for the subsequent degradation catalytic reaction without successive H2O2, resulting in the inexpensive and the effective photocatalytic procedure. As a result, 100% nitrobenzene (100 mg/L) was degraded and 97% of the organic carbon was mineralized in 90 min using the Fe2Ox/C (0.1 g/L) at a low H2O2 dosage (0.50 mM), under air mass (AM) 1.5 irradiation. Theoretical calculations confirmed that the Fe2Ox/C-600 with thin carbon layer promoted the dissociation of H2O2 and the ·OH desorption. The synergistic catalysis of this work may provide new ideas for low-cost and more efficient treatment of pollutants.