Abstract:

Using urea and L-glutamine (Lg) as precursor materials, Lg molecules were successfully linked to the edge of carbon nitride (CN) by freezing-calcination method, and Lg grafted porous carbon nitride (LCN) photocatalysts with excellent photocatalytic performance were prepared. The morphological structure and photocatalytic performance of the samples were tested by X-ray spectroscopy (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The results showed that the introduction of Lg molecular chains could not only increase the specific surface area of the material and provide more active sites, but also effectively promote the rapid separation and transfer of photogenerated electrons, resulting in excellent photocatalytic activity. Under visible light irradiation, the hydrogen formation rate of LCN-10 photocatalyst with the optimal mass ratio during hydrogen evolution test was up to 658µmol/(g·h), about 3 times higher than that of pure phase CN. LCN-10 also indicated good catalytic activity in photodegradation tests of tetracycline hydrochloride (TCH) and levofloxacin (LEV), achieving 98% as well as 85% photodegradation of TCH and LEV within 60min. This work provided a new perspective on the surface modification and performance optimization of CN-based photocatalytic materials.

Key words: photocatalysis, hydrogen production, degradation, carbon nitride, L-glutamine

摘要：

将尿素和L-谷氨酰胺（Lg）作为前体材料，使用冷冻-煅烧法成功将Lg分子链接枝到了氮化碳（CN）的边缘，制备了具有优异光催化性能Lg接枝修饰的多孔氮化碳（LCN）光催化剂。通过X射线衍射光谱（XRD）、扫描电子显微镜（SEM）、傅里叶变换红外光谱（FTIR）、X射线光电子能谱（XPS）等表征测试方法对样品的形貌结构以及光催化性能进行了测试。结果表明，Lg分子链的引入不仅能够增加材料的比表面积，提供更多的活性位点，同时还可以有效促进光生电子的快速分离和转移，从而获得优异的光催化活性。在可见光的照射下，最优质量比的LCN-10光催化剂在析氢测试过程中产氢速率高达658µmol/(g·h)，约是纯相CN的3倍。并且在光降解盐酸四环素（TCH）和左氧氟沙星（LEV）的测试中，LCN-10也表现出良好的催化活性，在60min内对TCH和LEV的光降解率达到了98%及85%。这项工作为CN基光催化材料的表面修饰与性能优化提供了新的视角。

关键词: 光催化, 制氢, 降解, 氮化碳, L-谷氨酰胺