A self-sufficient photo-Fenton system with coupling in-situ production H2O2 of ultrathin porous g-C3N4 nanosheets and amorphous FeOOH quantum dots.

Photo-Fenton degradation of pollutants in wastewater involving hydrogen peroxide (H2O2) and Fe2+ ions to produce hydroxyl radicals (·OH) with high oxidative activity is an ideal and feasible choice in advanced oxidation processes (AOPs). However, the photo-Fenton degradation application is limited by the range of acidic pH and the external introduction of H2O2 and Fe2+ ions. Herein, a self-sufficient photo-Fenton system was developed by coupled ultrathin porous g-C3N4 (UPCN) nanosheets that spontaneously produce H2O2 with amorphous FeOOH quantum dots (QDs) via in-situ deposition method for efficient photo-Fenton degradation of oxytetracycline (OTC) under natural pH condition. The enhancement of photocatalytic degradation activity comes from the synergistic effect of amorphous FeOOH QDs and UPCN nanosheets as follows: on the one hand, the formation of photo-Fenton system combining in-situ generation H2O2 of UPCN with amorphous FeOOH QDs can better boost photocatalytic activity for degrading OTC solution in natural pH under light illumination; on the other hand, the ultrathin porous structure of UPCN can better promote the rapid transfer and dispersion of photo-generated electrons from UPCN to amorphous FeOOH QDs and then Fe3+ is reduced to Fe2+ to participate in the Fenton catalytic reaction.