原位制备SrSb2O6/g-C3N4新型二维异质结用于可见光催化降解四环素的研究

本文采用高温固相原位制备新型二维SrSb_2O_6/g-C_3N_4异质结光催化复合材料,并将其用于可见光催化降解四环素。通过XRD和FT-IR谱对其结构进行表征。光催化降解实验表明,异质结复合材料较母体g-C_3N_4和SrSb_2O_6而言,光催化效率均得到了提升。其中,异质结样品SSO-CN-2对四环素溶液具有最优的光催化降解效率,其降解率在240min达到62%,分别是母体g-C_3N_4和SrSb_2O_6的2.5和46.0倍。光催化动力学实验表明,其降解曲线符合准一级动力学模型,速率常数为3.920×10~(-3)min~(-1)。循环实验表明,异质结样品的光催化降解性能表现稳定并且结构稳定性较高。活性自由基捕获实验表明,·O~-_2是主要催化反应的活性物种,光催化机理可用半导体异质结Type-II类型得到解释。

In-site Preparation of Novel Two Dimensional Heterjunction SrSb2O6/g-C3N4 for the Photodegradation of Tetracycline under Visible Light Irradiation

In this paper, novel two-dimensional SrSb2O6/g-C3N4 heterojunction was prepared by solid-state method, and the as-prepared photocatalysts were applied to evaluated the photodegradation of tetracycline. The phase of the as-synthesized samples was characterized by powder X-ray diffraction and Fourier Transform Infrared Reflectance Spectroscopy. The results of the photocatalytic degradation indicate that the photocatalytic performance of heterojunction is higher than that of parent compound g-C3N4 and SrSb2O6. Among them, the heterojunction named SSO-CN-2 exhibits the best performance and the photodegradation rate achieves 62% in 240 min, which is 2.5 and 46 times as compared with g-C3N4 and SrSb2O6. The mechanism of photocatalytic degradation could be described by a pseudo first order kinetic model, and the fitted rate constant was 0.00392 min-1 for sample SSO-CN-2. The cycling runs demonstrated that the stability of photodegradation and phase. Finally, the active free radical trappinge experiment revealed that the superoxide radical anion (?O2-) is the main active species. The photocatalytic process could well be explained by mechanism of heterojunction Type-II.