【摘要】 采用水热法将TiO₂纳米片修饰在中空管状g-C₃N₄上制备了TiO₂/g-C₃N₄（T-CN）复合催化剂。利用扫描电子显微镜（SEM）、X射线光电子能谱（XPS）、紫外可见漫反射光谱（UV-Vis DRS）和光电流响应等对其形貌、结构和光物理性能进行了表征。结果表明，TiO₂纳米片均匀地分散在中空管状g-C₃N₄表面，两者紧密结合形成异质结。TiO₂与g-C₃N₄的质量比为20%时制得的T-CN-20复合催化剂在60 min内对U的去除率为85.64%，是纯相g-C₃N₄的6.7倍。在10倍高浓度阳离子共存条件下的去除率仍大于69.8%，且具有优良的结构稳定性。对光催化产物分析可知，T-CN将U还原为难溶的U（63.68%）以去除铀，可有效解决含铀核废水中的U污染问题。根据能带理论分析，提出了复合催化剂异质结的Ⅱ型光催化机理。更多还原

【Abstract】 TiO₂/g-C₃N₄（T-CN） composite catalyst was successfully prepared by hydrothermal reaction of hollow tubular g-C₃N₄and TiO₂nanosheets. Its morphology, structure, and photophysical properties were characterized by scanning electron microscopy（SEM）, X-ray photoelectron spectroscopy（XPS）, UV-visible diffuse reflectance spectrum（UV-Vis DRS）, and photocurrent response. The effect of different amounts of TiO₂on the photoreduction and fixation of U（Ⅵ） by T-CN was studied. The results showed that when the mass ratio of TiO₂to g-C₃N₄was 20%, the removal rate of U（Ⅵ） by T-CN-20 was 85.64% in 60 min, which was 4.0 times of that of pure phase g-C₃N₄. The removal rate of U（Ⅵ） was still more than 69.8% under the coexistence of 10 times of high concentration cations, and had excellent structural stability. According to the analysis of photocatalytic products, T-CN-20 reduced U（Ⅵ） to insoluble U（Ⅵ）（63.68%） for removal, which can effectively solve the problem of U（Ⅵ） pollution in uranium-containing nuclear wastewater. Based on the analysis of energy band theory, the type-Ⅱ photocatalysis mechanism of composite catalyst heterojunction was proposed.更多还原