Xu Peng, Chen Nannan, Lin Huan, Cen Changli, Wu Zhenguo, Xu Nanfang, Tang Jingen, Teng Zhaogang
College of Chemical Engineering, Nanjing Forestry University, Nanjing 210037, China.
College of Forestry, Nanjing Forestry University, Nanjing 210037, China.
J Nanosci Nanotechnol. 2018 Dec 1;18(12):8307-8312. doi: 10.1166/jnn.2018.16412.
Anchoring metal cores inside porous shells can endow metal catalyst with high selectivity and stability. Herein, multiple silver nanoparticles were successfully anchored in hollow mesoporous silica nanospheres (Ag@HMSNs) through a facile one-pot method. Polyacrylic acid aggregates self-assembled in water/ethanol solvent were used as core templates and Ag nanoparticles captors, and hexadecyl trimethoxysilane (C16TMS) was used as the pore-making agent. The hollow cavity, encapsulated multiple Ag nanoparticles, and mesoporous silica shell of the Ag@HMSNs were confirmed by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and nitrogen sorption analysis. Just as expected, Ag nanoparticles (2-5 nm) were encapsulated in the cavity of hollow mesoporous silica nanospheres with the size of about 200 nm. The fabricated Ag@HMSNs showed excellent performance for catalytic reduction of p-nitrophenol (4-NP). Also, catalytic activity of the Ag@HMSNs for 4-NP reduction was increased with the addition amount of the pore-making agents and surface areas. The superior catalytic performance was attributed to the unique structural features of Ag@HMSNs architecture, in which the mesoporous shell provided readily accessible pathway for fast transport of reactants to the encapsulated Ag nanoparticles.
将金属核锚定在多孔壳内可赋予金属催化剂高选择性和稳定性。在此，通过简便的一锅法成功地将多个银纳米颗粒锚定在中空介孔二氧化硅纳米球（Ag@HMSNs）中。在水/乙醇溶剂中自组装的聚丙烯酸聚集体用作核模板和银纳米颗粒捕获剂，十六烷基三甲氧基硅烷（C16TMS）用作造孔剂。通过X射线粉末衍射（XRD）、透射电子显微镜（TEM）和氮吸附分析证实了Ag@HMSNs的中空腔、包封的多个银纳米颗粒和介孔二氧化硅壳。正如预期的那样，银纳米颗粒（2-5纳米）被封装在尺寸约为200纳米的中空介孔二氧化硅纳米球的腔内。制备的Ag@HMSNs对催化还原对硝基苯酚（4-NP）表现出优异的性能。此外，Ag@HMSNs对4-NP还原的催化活性随着造孔剂添加量和表面积的增加而提高。优异的催化性能归因于Ag@HMSNs结构的独特结构特征，其中介孔壳为反应物快速传输到包封的银纳米颗粒提供了易于接近的途径。
