The trapezoidal heterojunction ZnO/Bi2O3 with 3D interfacial structure for the efficient degradation of organic pollutants

Z-scheme photocatalysts offer a solution to the limitations of traditional single-semiconductor photocatalysts. Their robust redox capabilities and efficient charge separation from photogenerated electrons make them particularly useful in addressing energy challenges and environmental pollution. In this study, we synthesized a novel Z-scheme ZnO/Bi2O3 (ZBO) photocatalyst using an in-situ hydrothermal method to expedite the degradation of tetracycline hydrochloride (TCH). The unique chemical composition of ZnO and Bi2O3, coupled with their synergistic effect, improving the number of multidimensional active sites and the efficiency of photogenerated electron pair separation. Notably, after 120 min, the TCH decomposition rate reached 91.1 %. The effects of initial pH, catalyst dosage, TCH concentration, and various coexisting anions were studied. It was discovered that pH and various anions had the greatest impact on the photocatalytic performance of ZBO for the breakdown of TCH. In addition, free radical capture experiments revealed that ·O2− and h+ were the most important reactive species that accelerated the photocatalytic activities of ZBO. Work function calculations demonstrated that the presence of internal electric field (IEF) in the special ZBO heterojunction, indicating the formation of a Z-scheme heterojunction, which greatly facilitated the separation of electron-hole pairs to promote efficient TCH degradation. This study provides a potential strategy for developing high-performance photocatalysts that can produce clean energy without negatively impacting the environment.