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

Abstract

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 α-F2O3 was successfully synthesized. Combining the experimental results and characterization, we extensively investigated the charge transfer mechanism of the α-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 α-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 ·O2− were the major active substances in the photocatalytic degradation process.