Preparation of defect-enriched Cu-doped FeOCl/g-C3N4 Z-scheme composites for efficient photo-Fenton-like performance

In this study, a Z-scheme heterojunction with abundant oxygen vacancies (OVs) formed by Cu-doped FeOCl (CuFeOCl) and graphitic carbon nitride nanosheets (CNNS) was successfully synthesized for the removal of tetracycline hydrochloride (TC). The prepared Cu-FeOCl/CNNS had excellent catalytic properties under hydrogen peroxide and light illumination, and the maximum reaction rate was nearly 156 and 48 times higher than that of FeOCl and CNNS, respectively. The enhancement of catalytic performance was due to the synergistic effect of Cu species, Fe species and Ovs, which effectively promoted the adsorption and activation of H2O2, and inhibited the recombination of photogenerated carriers. We further studied the effects of different reaction conditions (catalyst dosage, H2O2 dosage, initial pH, TC concentration, and coexisting substances) on the degradation reaction. O-1(2), h(+), center dot O-2(-), and center dot OH were active species participating in the reaction, and a possible TC degradation mechanism was studied. This work provided insights into the synergetic action of interface engineering, ion doping, and oxygen defects in the photo-Fenton-like system.