板状NH_2-SBA-15的一步合成及其吸附性能

One-step Synthesis and Adsorption Properties of Platelet NH_2-SBA-15

以3-氨丙基三甲氧基硅烷(APTMS)为功能化试剂,采用水热一步合成法制备出氨基功能化材料NH_2-SBA-15。通过X射线衍射、扫描电镜、透射电镜、Fourier红外光谱、N_2吸附-脱附和X射线能谱(EDS)对NH_2-SBA-15的介孔结构、氨基的负载进行了表征。结果表明,与板状SBA-15相比,氨基功能化样品NH_2-SBA-15同样具有板状形貌和二维六方的短孔道介孔结构;随着APTMS量的增加,样品中嵌入的氨基物种增多,样品的短程有序性变差,比表面积降低,孔径减小,部分孔道口发生堵塞。对阴离子染料刚果红的吸附实验表明,氨基功能化后试样的吸附能力增强,其中,APTMS/正硅酸乙酯(TEOS)摩尔比为0.2的试样吸附效果最好,50 mg试样室温下吸附100 m L的0.30mmol/L的刚果红溶液,6 min后达到吸附平衡,吸附率为97.5%;试样对刚果红的饱和吸附量可达0.60 mmol/g。

An amino-functionalized mesoporous material （NH2-SBA-15） was synthesized by one-step hydrothermal synthesis using 3-aminopropyltrimethoxysilane （APTMS） as functionalized agent. The structure and functional groups loading of the materials were characterized by X-ray diffraction （XRD） , scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, Fourier transform infrared spectroscopy, nitrogen adsorption desorption and energy dispersive spectrometer （EDS） techniques. The results showed that NH2-SBA-15 with platelet morphologies and two-dimensional hexagonal short vertical channels, similar to platelet SBA-15, was synthesized. With the increasing of the amount for APTMS the amino loading embedded within the structure increased, the short range ordering declined, the specific surface area and the pore size decreased, and a few opening channels were blocked. The adsorption experiments for anionic dye Congo red proved the amino-functionalization has improved adsorption performance of mesoporous materials. The material with 0. 2 APTMS/tetraethyl orthosilicate （TEOS） molar ratio had higher adsorption capacities. At room temperature 100 mL of 0.30 mmol/L Congo red solution are adsorbed by 50 mg sample, the adsorption equilibrium is reached after 6 min and the adsorption percentage is 97.5% ,the saturated adsorption amount reached 0.60 mmol/g.