草酸增效掺铁石墨相氮化碳的光催化性能

Oxalic Acid Enhanced the Photocatalytic Performance of Fe^(3+) Doped g-C_3N_4

以硝酸铁和三聚氰胺为原料,制备了掺铁石墨相氮化碳(Fe-C_3N_4)。通过扫描电子显微镜、X射线衍射、傅里叶变换红外光谱、X光电子能谱和紫外可见光漫反射光谱对催化剂形貌和理化性质进行了表征。结果表明,铁掺杂改变了g-C_3N_4材料的能带结构,增加了g-C_3N_4对可见光的吸收范围。草酸能够有效提高Fe-C_3N_4体系光催化降解亚甲基蓝过程的降解率,2 h内降解率达到98.9%,分别是单独g-C_3N_4、Fe-C_3N_4和草酸加g-C_3N_4体系光催化降解亚甲基蓝的2.98、2.16和1.81倍。自由基捕获实验证明空穴和HO~·在脱色过程中起到主要作用。

The Fe3+ doped g-C3N4photocatalyst(Fe-C3N4) was prepared using ferric nitrate and melamine as raw materials. The morphology and physicochemical properties of photocatalyst was characterized by transmission microscope, X-ray diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy and ultraviolet-visible spectroscopy(UV-vis), respectively. The results showed that presence of Fe3+ simultaneously changed energy band structure and visible light absorption range of g-C3N4. The photocatalytic performance of methylene blue was strengthened for the oxalic acid assisted Fe-C3N4 photocatalysis system under simulated solar-light irradiation, and 98.9% of methylene blue was decolorized within 120 min. The removal efficiency increased by 2.98, 2.16 and 1.81 times compared with the single g-C3N4, Fe-C3N4, oxalic acid and g-C3N4 photocatalyst, respectively. The quenching experiment demonstrated that hole and·OH played a major role in the photocatalytic degradation of methylene blue in the presence of oxalic acid.