Ti₃C₂/CN-X光催化剂的制备实验及其性能表征

Preparation and Performance Characterization of Ti₃C₂/CN-X Photocatalyst

摘要: 介绍一个综合化学实验——Ti₃C₂/CN-X光催化剂的制备及其性能表征。针对石墨相氮化碳存在光生载流子复合率高、比表面积有限，光催化产氢活性不足的问题，本研究面向化学类高年级本科生设计开发一项材料光催化方向综合化学教学实验。实验采用氢氟酸选择性刻蚀Ti₃AlC₂制备少层Ti₃C₂ (MXene)，以盐辅助焙烧法得到改性氮化碳CN‑X，进一步通过液相超声复合工艺构建不同Ti₃C₂负载比例的Ti₃C₂/CN‑X异质结光催化材料；借助XRD、SEM‑EDS以及光催化分解水产氢测试系统完成材料的结构表征与性能评价。实验结果表明，当Ti₃C₂负载质量分数为10%时，Ti₃C₂/CN‑X复合材料产氢速率可达78.2 µmol/h/g，相较纯CN‑X提升显著。该实验将前沿MXene基光催化科研成果转化为本科教学项目，可训练学生材料合成、仪器表征与性能评价的综合实验技能，帮助学生理解异质结光催化作用机制，培养科研思维与创新兴趣，适合纳入化学相关专业高年级综合化学实验课程。

Abstract: This work introduces a comprehensive chemistry experiment on the preparation and performance characterization of Ti₃C₂/CN-X photocatalysts. Aiming at the drawbacks of graphitic carbon nitride, including high recombination rate of photogenerated charge carriers, limited specific surface area and insufficient photocatalytic hydrogen‑evolution activity, this work develops a comprehensive chemistry teaching experiment on material photocatalysis for senior undergraduates majoring in chemistry. Few‑layer Ti₃C₂ (MXene) is synthesized via selective hydrofluoric‑acid etching of Ti₃AlC₂. Modified carbon nitride CN‑X is obtained by a salt‑assisted calcination strategy. Ti₃C₂/CN‑X heterojunction photocatalysts with varied Ti₃C₂ loadings are further fabricated through liquid‑phase ultrasonic compounding. X‑ray diffraction (XRD), scanning electron microscopy coupled with energy‑dispersive X‑ray spectroscopy (SEM‑EDS), and a photocatalytic water‑splitting hydrogen‑evolution test system are employed for structural characterization and performance evaluation of the as‑prepared materials. Experimental results demonstrate that the Ti₃C₂/CN‑X composite with 10 wt% Ti₃C₂ achieves an optimal hydrogen‑evolution rate of 78.2 µmol·h⁻¹·g⁻¹, exhibiting a remarkable improvement compared with pure CN‑X. Translating cutting‑edge research achievements of MXene‑based photocatalysis into an undergraduate teaching program, this experiment can train students’ comprehensive experimental skills in material synthesis, instrumental characterization and performance assessment. It also facilitates students’ understanding of the heterojunction photocatalytic mechanism and cultivates their scientific thinking and innovative interest. Hence, it is suitable to be incorporated into the comprehensive chemistry experiment curriculum for senior students majoring in chemistry‑related disciplines.