Solar-driven efficient degradation of emerging contaminants by g-C3N4-shielding polyester fiber/TiO2 composites

Solar-driven photocatalysis has shown tremendous potential for environmental remediation, but photocatalysts with the strong oxidation ability usually destroy some organic carriers. Herein, we constructed a graphitic carbon nitride (g-C3N4)-shielding polyester fiber (PET)/titanium dioxide (TiO2) composite (g-C3N4-TiO2@LMPET) by using g-C3N4 as an isolation layer to protect the PET from the oxidation damage by hydroxyl radicals (OH). The results of photoluminescence and photocurrent indicated that the g-C3N4-TiO2@LMPET has lower photogenerated charge recombination rate. Meanwhile, g-C3N4 broadens the absorption range of the composite to visible region. Therefore, the g-C3N4-TiO2@LMPET composite exhibited a significantly enhanced photocatalytic performance toward the degradation of sulfaquinoxaline (SQX) and thiamethoxam under solar irradiation. Moreover, the g-C3N4-TiO2@LMPET exhibited good repeatability in cyclic experiments. Finally, the possible degradation pathways and mechanisms of SQX and thiamethoxam were proposed. Overall, our work provides a feasible method for constructing efficient and stable photocatalytic materials to eliminating emerging contaminants.