| N和F共掺杂C3N4的制备及其可见光催化性能 | |
| Preparation and Visible Light Photocatalytic Properties of N and F Co-doped C3N4 | |
| 摘要: 针对氮化碳（C3N4）光生电荷易复合、光催化性能有限的不足，我们制备N和F共掺杂C3N4（NF-C3N4），以提升其光催化性能。利用NH4F在高温下原位分解产生的HF和NH3，对C3N4刻蚀的同时实现N和F双元素共掺杂。以氯化铵（NH4Cl）为对照，制备N掺杂C3N4（N-C3N4）。利用扫描电子显微镜（SEM）、能谱仪（EDS）、X射线光电子能谱（XPS）、X射线衍射（XRD）、比表面积测试和电化学表征手段研究N、F共掺杂对C3N4形貌、成分、结构和物化性质等的影响规律。相比于C3N4和N-C3N4，NF-C3N4呈多孔状，比表面积增大，光生电荷的生成、分离和转移均被促进，NF-C3N4光催化还原Cr （Ⅵ）的速率是C3N4的2.6倍、N-C3N4的1.7倍。进一步考察了不同前驱体（尿素、双氰胺和三聚氰胺）对制备C3N4的影响，发现以尿素为前驱体的C3N4与NH4F的质量比为3∶2时，NF-C3N4呈现最佳的光催化性能。催化剂用量、光照强度、空穴捕获剂浓度的增加和pH的降低均能提高Cr （Ⅵ）还原速率。在NF-C3N4浓度为0.1 g·L-1、pH=3、cEDTA-2Na=2 mmol·L-1、40 min可见光照射后，Cr （Ⅵ）去除率达到90%。5次循环实验表明，优化制备的NF-C3N4光催化还原Cr （Ⅵ）的性能保持良好，具有较高的稳定性。 | |
| 关键词: 光催化 C3N4 Cr(Ⅵ)还原 N、F共掺杂 | |
| 基金项目: 国家自然科学基金（No.21876154）、浙江省属高校基本业务费专项资金（No.JRK22001）、浙江师范大学“先进催化材料”教育部重点实验室和浙江省“固体表面反应化学”重点实验室开放课题（No.KLMEACM202104）、浙江省教育厅一般科研项目（No.Y202147596）资助 | |
| Abstract: To overcome the shortcomings of carbon nitride (C3N4), such as easily recombination of photogenerated charges and limited photocatalytic activity, this study explored a method to prepare NF-C3N4 via co-doping of N and F into C3N4 with improved photocatalytic performance.Using HF and NH3 produced by the in-situ decomposition of NH4F at high temperature, dual elements doping was achieved while etching C3N4.N-doped C3N4 (N-C3N4) was prepared by using ammonium chloride (NH4Cl) as a control sample.The effects of N and F co-doping on the morphology, composition, structure, and physicochemical properties of C3N4 were studied using scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), specific surface area, and electrochemistry.Compared with C3N4 and N-C3N4, NF-C3N4 had porous and increased specific surface area, and the generation, separation, and transfer of photogenerated charges were promoted.The photocatalytic reduction rate of Cr(Ⅵ) by NF-C3N4 was 2.6 times that of C3N4 and 1.7 times that of N-C3N4, respectively.The influence of different precursors(urea, dicyandiamide, and melamine)on the preparation of C3N4 was further investigated.It was found that when the mass ratio of C3N4 with urea as a precursor to NH4F was 3:2, NF-C3N4 showed the best photocatalytic performance.Furthermore, the reduction rate of Cr(Ⅵ) can be enhanced with the increase of catalyst dosage, light intensity, hole trapping agent concentration, and decrease in pH.After 40 min visible light irradiation with 0.1 g·L-1 NF-C3N4, pH=3 and cEDTA-2Na=2 mmol·L-1, the Cr(Ⅵ) removal efficiency reached 90%.Five cyclic runs indicated that the optimized NF-C3N4 remained good performance and high stability for photocatalytic reduction of Cr(Ⅵ). | |
| Keywords: photocatalysis C3N4 Cr(Ⅵ) reduction N and F co-doping | |
| 投稿时间：2022-05-30 修订日期：2022-08-15 | |
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| 薛彪,傅炀杰,谭盟,张超,李宁毅,杨凌轩,郑淑贞,王齐.N和F共掺杂C3N4的制备及其可见光催化性能[J].无机化学学报,2022,38(10):2047-2055. | |
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