| 大孔-介孔Ag/PDA/MMS复合材料的制备及其催化性能 |
| Preparation and catalytic performance of macro-mesoporous Ag/PDA/MMS composite |
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| 摘要: 用双模板法制备了介孔纳米薄膜构筑的毫米级尺寸的大孔-介孔SiO2(MMS),通过多巴胺(DA)在其孔道表面氧化自聚合成聚多巴胺(PDA),得到PDA修饰的MMS (PDA/MMS),再经PDA原位还原Ag+制得大孔-介孔Ag/PDA/MMS复合材料。应用扫描电镜、透射电镜、N2吸附-脱附、X射线光电子能谱、X射线衍射、UV-Vis、FT-IR和热重技术对所制得的材料进行表征。结果表明,MMS兼具纳米介孔材料和宏观尺寸大孔材料的优点。Ag/PDA/MMS在催化还原对硝基苯酚(4-NP)反应中展现出高催化活性,转化频率(TOF)达2.97 min-1。这归因于其独特的结构:相互连通的大孔孔道大大降低了传质阻力,短孔道的介孔显著增加了活性位点的可达性,大的比表面积为反应物提供了大量的活性位点。而且,毫米级尺寸的Ag/PDA/MMS可以很容易从反应体系中分离出来,在5次循环后仍能将4-NP完全转化为对氨基苯酚(4-AP)。另外,Ag/PDA/MMS对亚甲基蓝(MB)的还原也有良好的催化效果。 |
| 关键词: 毫米级尺寸 介孔纳米薄膜 多级孔二氧化硅 聚多巴胺 银纳米粒子 对硝基苯酚 亚甲基蓝 |
| 基金项目: 浙江省公益技术研究项目(No.LGG19E020002)资助。 |
| Abstract: A millimeter-sized macro-mesoporous SiO2 (MMS) was prepared by a dual-templating method, using an epoxy resin macroporous polymer with 3D skeleton structure as the macroscopic shape and macropore structure directing agent and PEG 2000 as the mesopore porogen and the PDA-modified MMS (PDA/MMS, PDA=polydopamine) was obtained via the oxidative self-polymerization of dopamine (DA) on the pore wall of MMS, then the in situ reduction of Ag+ by the PDA on the surface of PDA/MMS formed the macro-mesoporous Ag/PDA/MMS composite. The as-prepared materials were characterized by scanning electron microscope, transmission electron microscope, N2 adsorption-desorption, X-ray photoelectron spectroscopy, X-ray diffraction, UV-Vis, FT-IR, and thermogravimetry techniques. The results show that MMS has the advantages of both nano-mesoporous materials and macro-sized macroporous materials, and possesses large specific surface area and pore volume, and high mechanical strength. Ag/PDA/MMS exhibited high catalytic activity in the reduction of p-nitrophenol (4-NP), and the turnover frequency (TOF) reached 2.97 min-1, which is attributed to its unique structure:the interconnected macropores greatly reduce mass transfer resistance, the short mesopore channels significantly increase the accessibility of active sites and effectively confine the size of silver nanoparticles, and the large specific surface area provides a large number of active sites for reactants. Moreover, the millimeter-sized Ag/PDA/MMS could be easily separated from the reaction system, and it could still convert 4-NP to p-aminophenol (4-AP) completely after five cycles. In addition, Ag/PDA/MMS also showed a good catalytic effect in the reduction of methylene blue (MB). |
| Keywords: millimeter-size mesoporous nanofilm hierarchical porous silica polydopamine silver nanoparticle p-nitrophenol methylene blue |
| 投稿时间：2023-01-02 修订日期：2023-04-14 |
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| 葛鑫峰,胡俊,王明辉,舒婷,梁云霄.大孔-介孔Ag/PDA/MMS复合材料的制备及其催化性能[J].无机化学学报,2023,39(5):906-916. |
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