ZIF-8/g-C3N4复合材料在四环素类抗生素废水处理中的可见光催化应用OA

In this study,the ZIF-8/g-C3N4 composite photocatalyst was prepared by an in-situ deposition method.Characterization techniques such as FT-IR,XRD and SEM were used to confirm that the regular dodecahedral ZIF-8 was uniformly wrapped by g-C3N4 nanosheets.TG analysis showed that the composite material had good thermal stability.The BET test results indicated that the presence of ZIF-8 significantly increased the specific surface area of the composite material,which was beneficial for the adsorption of tetracycline.The UV-Vis diffuse reflection spectrum showed that the visible light absorption edge of the composite material had a significant red shift.The transient photocurrent density and electrochemical impedance test results confirmed that the carrier separation efficiency of the composite material was significantly optimized.In the visible light-driven degradation experiment of tetracycline,ZIF-8/g-C3N4 achieved a degradation efficiency of 87.93％within 120 minutes,which was 2.35 times and 1.34 times that of single ZIF-8 and g-C3N4 respectively.After five cycles,the activity only decreased by 4.23％,demonstrating excellent stability.Mechanistic studies showed that the main active species in the system was·OH-.The type Ⅱ heterojunction constructed between ZIF-8 and g-C3N4 promoted the directional migration of photogenerated electrons through band matching and inhibited the recombination of carriers.The combination of the two not only increased the specific surface area of the material but also broadened the visible light response range,thus significantly improving the photocatalytic performance.