The Construction of an -F₂O₃/Tubular g-C₃N₄ Z-Scheme Heterojunction Catalyst for the Efficient Photocatalytic Degradation of Tetracycline

Morphological engineering and semiconductor coupling show significant potential to increase the photocatalytic performance of graphite carbon nitride (g-C3N4). In this work, a unique Z-scheme heterojunction photocatalyst composed of tubular g-C3N4 (TCN) and alpha-F2O3 was successfully synthesized. Combining the experimental results and characterization, we extensively investigated the charge transfer mechanism of the alpha-F2O3/tubular g-C3N4 (FO-TCN) heterojunctions and processes in the photocatalytic degradation of tetracycline (TC). The tubular morphology provided a larger specific surface area, enhancing the light absorption area and thus improving the exposure of the active sites. Not only was the light absorption range expanded through the coupling with alpha-F2O3, but the charge transfer properties of the sample were also strengthened. The synergism between photocatalysis and the Fenton reaction enhanced the photocatalytic performance of the FO-TCN. Due to the previously mentioned beneficial factors, the performance of the FO-TCN photocatalyst was significantly increased; its reaction rate k value in the degradation of TC (0.0482 min(-1)) was 4.05 times faster than that of single g-C3N4 and it exhibited the best photocatalytic performance (95.02%) for the degradation of TC in 60 min, with an enhancement of 38.41%. Quenching experiments showed that h(+) and O-2(-) were the major active substances in the photocatalytic degradation process.