氨基修饰片状氮化碳的制备及光催化性能

石墨相氮化碳是一种低成本易获得的可见光响应光催化剂，但由于比表面积小、光生载流子易复合等缺点限制了其应用。为克服传统氮化碳的缺陷，本实验以尿素和三聚氰胺为原料，通过水热预处理改性前体，再用高温煅烧法成功制备出氨基修饰片状氮化碳光催化材料。并通过X射线衍射（XRD）、扫描电子显微镜（SEM）和X射线光电子能谱仪（XPS）等手段对样品的晶格结构和形貌特征等进行表征。结果表明，成功引入氨基基团的片状氮化碳，比表面积增加且光生载流子复合率显著降低。以罗丹明B和壬基酚溶液的光降解考察材料光催化性能，发现氨基修饰片状氮化碳对其去除率分别为80.69%和50.7%，分别是传统块状氮化碳的2.45倍和2.19倍，是未修饰片状氮化碳的1.26倍和1.21倍。且氨基修饰片状氮化碳材料重复使用5次后仍具有较高光催化活性，光催化性能显著提高。

Preparation and photocatalytic activity of amino-modified sheet-like carbon nitride

Graphitic carbon nitride is a low-cost and accessible photocatalyst with visible light-responsive region. However, low specific surface area and fast recombination of photogenerated carriers limit its practical application. To overcome the above defects of traditional carbon nitride, the urea and melamine were employed to prepare precursors by hydrothermal pretreatment. After that, amino-modified sheet-like carbon nitride was successfully synthesized by calcinating the precursors with high-temperature. The crystal lattice structure, morphology and other properties of the sample were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS) and so on. The results showed that the specific surface area was increased and the photocarrier recombination rate was decreased significantly after the introduction of amino groups into the sheet-like carbon nitride. In order to test the performance of the photocatalytic materials, Rhodamine B and nonylphenol were identified as the target pollutants. The removal rates of Rhodamine B and nonylphenol with amino-modified sheet-like carbon nitride were 80.69% and 50.7%, respectively, which was 2.5 and 2.2 times higher than that of traditional bulk carbon nitride, and 1.3 and 1.2 times higher than that of unmodified sheet-like carbon nitride, respectively. In addition, after five times cycle, the amino-modified sheet-like carbon nitride still possessed high photocatalytic activity. In summary, the photocatalytic performance of amino-modified sheet-like carbon nitride was significantly improved.