A Z-Scheme Heterojunction g-C₃N₄/WO₃ for Efficient Photodegradation of Tetracycline Hydrochloride and Rhodamine B

The construction of heterojunctions can effectively inhibit the rapid recombination of photogenerated electrons and holes in photocatalysts and offers great potential for pollutant degradation. In this study, a Z-scheme heterojunction g-C₃N₄/WO₃ photocatalyst was synthesized using a combination of hydrothermal and calcination methods. The photocatalytic degradation performance was tested under visible light; the degradation efficiency of Rh B reached 97.9% within 15 min and that of TC-HCl reached 93.3% within 180 min. The excellent photocatalytic performance of g-C₃N₄/WO₃ composites can be attributed to the improved absorption of visible light, the increase in surface area, and the effective separation of photogenerated electron-hole pairs. In addition, after four cycles of experiments, the photocatalytic performance of g-C₃N₄/WO₃ did not decrease obviously, remaining at 97.8%, which proved that the g-C₃N₄/WO₃ heterojunction had high stability and reusability. The active radical capture experiment confirmed that h⁺ and ·O₂^- played a leading role in the photocatalytic degradation. The Z-scheme heterojunction g-C₃N₄/WO₃ designed and synthesized in this study is expected to become an efficient photocatalyst suitable for environmental pollution control.