Abstract:

In this study, iron-based nitrogen-deficient three-dimensional carbon nitride catalysts [Fe(Ⅲ)/3D CN-Nv] with varying loadings were synthesized via a thermal shrinkage polymerization impregnation method. A photocatalytic self-Fenton system was constructed by coupling photocatalysis with Fenton technology for the efficient degradation of recalcitrant tetracycline hydrochloride pollutants. The results demonstrated that under visible light irradiation, the 1.5% Fe(Ⅲ)/3D CN-Nv catalyst achieved a 75.8% removal efficiency within 60min, which was 5 times higher than that of bulk g-C₃N₄ and 1.8 times higher than the catalyst without Fe(Ⅲ) impregnation. The enhanced performance was attributed to the formation of Fe-N bonds within the triazine ring structure, facilitating electron transfer from Fe³⁺ to Fe²⁺ and improving the separation efficiency of photogenerated electrons. Additionally, the system generated H₂O₂insitu under visible light, which reacted with Fe²⁺ to produce hydroxyl radicals (·OH) for efficient pollutant degradation. The reaction conditions were optimized by investigating the effects of pH and Fe loading, and the primary reactive species responsible for tetracycline degradation were identified. This photocatalytic Fenton system demonstrates significant potential for applications in environmental remediation.

Key words: photo-Fenton, carbon nitride, in-situ H₂O₂ generation, tetracycline, iron doping

摘要：

通过热收缩聚合浸渍法合成了不同质量分数的铁基氮缺陷三维氮化碳催化剂［Fe(Ⅲ)/3D CN-Nv］，构建了光催化与Fenton技术耦合的光催化自Fenton体系，用于高效降解难处理的盐酸四环素污染物。结果表明，在可见光照射下，1.5% Fe(Ⅲ)/3D CN-Nv催化剂在60min内实现了75.8%的去除率，是bulk g-C₃N₄的6倍，较未浸渍Fe(Ⅲ)催化剂高1.8倍。性能提升主要归因于Fe－N键的形成，促进了Fe³⁺/Fe²⁺的电子转移，提高了光生电子的分离效率。此外，该体系在可见光下原位生成H₂O₂，并与Fe²⁺反应生成·OH，实现高效降解。通过优化pH及Fe负载量，确定了最佳反应条件，并明确了主要活性物种。该催化剂体系在环境污染治理中展现出广阔的应用前景。

关键词: 光芬顿, 氮化碳, 原位产H₂O₂, 四环素, 铁掺杂