Synergistic improving photo-Fenton and photo-catalytic degradation of carbamazepine over FeS2/Fe2O3/organic acid with H2O2 in-situ generation

Herein, a heterogeneous photo-Fenton and photo-catalytic system was constructed using oxide pyrite (FeS2/Fe2O3) mineral and organic acids including tartaric acid (TA), ascorbic acid (AA), and citric acid (CA). In the proposed system, FeS2/Fe2O3 can be successfully activated through irradiation to generate photogenerated carriers, which generated H2O2in-situ through the reduction reactions between e- and O2. The addition of organic acids enhanced the dissolution of iron from FeS2/Fe2O3. Based on the iron and in-situ generated H2O2, •OH was produced through a photo-Fenton reaction. Furthermore, h+, e-, and •O2-, which were generated through the photo-catalytic activation of FeS2/Fe2O3, also played a certain role in the degradation of carbamazepine (CBZ). Therefore, the synergistic photo-Fenton and photo-catalytic reaction improved the degradation of CBZ, with the degradation efficiencies of 86%, 62%, and 68% in FeS2/Fe2O3/TA, FeS2/Fe2O3/AA, and FeS2/Fe2O3/CA systems, respectively. This investigation provides an innovative strategy for the removal of organic pollutants using natural minerals.