Preparation of Porous SiO2 Materials from Tobermorite and Its Adsorption Performance
-
摘要: 通过水热合成制备具有良好的结晶形态的托贝莫来石（TOB），用不同温度对TOB进行加热活化（H-TOB），然后对H-TOB进行酸处理成功制备出多孔二氧化硅材料（300AH-TOB），并用XRD、N2吸-脱附、SEM、TEM等测试方法对多孔SiO2材料进行表征，研究了其形成机理。结果表明，制备的多孔SiO2材料比表面积达到了570.25 m2/g，总孔容为0.747 m3/g。TOB经过热活化和酸处理后，钙离子选择性溶出，TOB的SiO2骨架保留下来，在TOB的链状八元环结构上原位形成大量的纳米尺度的孔结构。通过静态吸附实验探讨了TOB、300H-TOB、300AH-TOB对碱性红2和结晶紫两种有机染料的吸附性能，在0.4 g的加入量下，TOB的吸附率分别为56.35%、47.69%；300H-TOB的吸附率为25.57%、42.69%；300AH-TOB吸附率为91.46%、88.86%。由托贝莫来石制备的多孔材料对有机染料具有良好的吸附作用，具有作为染料吸附剂的应用潜力。Abstract: Tobermorite (TOB) was major phase of calcium silicate board and autoclaved aerated concrete, which were widely used refractory materials and thermal insulation materials in the building engineering field. However, these materials were easy to wear so that large quantities of solid wastes have been produced. The problem of functionalized utilization of TOB needed to be resolved urgently. In the present paper, TOB samples with good crystal morphology were prepared by hydrothermal synthesis and were calcined at different temperature (H-TOB). Then the porous SiO2 material (300AH-TOB) was successfully prepared by acid treatment of H-TOB, and the porous SiO2 material was characterized by XRD, N2 adsorption-desorption, SEM, TEM and other testing methods to investigated the formation mechanism. The BET and pore size distribution test analysis showed that the specific surface area of 300AH-TOB after thermal activation at 300 ℃ and hydrochloric acid modification was 570.25 m2/g, and the total pore volume was 0.747 m3/g. After heat treatment and hydrochloric acid treatment, the calcium ions in TOB were selectively dissolved, and the main component of the acid-insoluble material was silica. Therefore, it was inferred that the silicon oxide exhibits an eight-membered ring double-chain deformation structure composed of a silicon-oxygen tetrahedron, resulting in an increase in mesopores and micropores. The adsorption performance of TOB, 300H-TOB and 300AH-TOB on two organic dyes, Safranine T and crystal violet, was investigated by static adsorption experiments. The adsorption rates were 56.35% and 47.69% for TOB; 25.57% and 42.69% for 300H-TOB; and 91.46% and 88.86% for 300AH-TOB, respectively, with the addition amount of 0.4 g. The porous material prepared from TOB had favorable adsorption of organic dyes, indicating its promising potential in adsorption application.
-
Key words:
- Tobermorite /
- Selective acid leaching /
- Porous silica /
- Adsorption
-
图 2 (a) 不同温度热处理TOB的XRD图谱；(b)煅烧托贝莫来石酸处理后的XRD图谱
Figure 2. XRD results of the calcined TOB samples (a) and the insoluble matters of the calcined TOB (b).
图 3 N2吸附-脱附等温线（a）和由2D-NLDFT方法计算的孔径分布曲线（b）
Figure 3. Nitrogen adsorption-desorption isotherms (a) and Pore size distribution curves calculated by 2D-NLDFT method (b)
图 4 TOB, 300H-TOB和300AH-TOB的SEM形貌
Figure 4. SEM morphology of TOB, 300H-TOB and 300AH-TOB
图 5 TOB, 300H-TOB和300AH-TOB的透射电镜形貌及衍射斑点图
Figure 5. TEM morphology and diffraction spectrogram of TOB (a), 300H-TOB (b), and 300AH-TOB (c)
图 6 TOB的多孔形成示意图
Figure 6. Schematic model for the possible formation of porous silica from TOB.
图 10 300AHTOB吸附CV的（a）Langmuir和（b）Freundlich等温吸附模型拟合
Figure 10. Langmuir and Freundlich isotherms for CV adsorption on 300AH-TOB
图 7 TOB、300H-TOB和300AH-TOB对碱性红2（a）和结晶紫（b）的吸附
Figure 7. TOB、300H-TOB and 300AH-TOB adsorption of basic red 2 (a) and crystal violet (b)
图 8 TOB, 300H-TOB和300AH-TOB的Zata电位图
Figure 8. Zeta potential of TOB, 300H-TOB and 300AH-TOB
图 9 300AHTOB吸附ST的（a）Langmuir和（b）Freundlich等温吸附模型拟合
Figure 9. Langmuir and Freundlich isotherms for ST adsorption on 300AH-TOB
表 1 TOB、300H-TOB、300AH-TOB的化学成分
Table 1. Chemical composition of TOB, 300H-TOB, 300AH-TOB
Sample SiO2/% CaO/% Others/% TOB 49.31 38.36 12.33 300H-TOB 54.71 42.56 2.73 300AH-TOB 90.11 0 9.89 
下载: 导出CSV
表 2 不同温度热活化TOB经过酸处理后的纳米孔道参数
Table 2. Porosity parameters of the HCl acid treatment samples pre-calcined at different temperatures.
Sample SBET/(m2/g) Sexternal/(m2·g−1) Smicro/(m2·g−1) Vmicro/(cm3·g−1) Vmeso/(cm3·g−1) Vt/(cm3·g−1) TOB 152.14 123.81 28.33 0.011 0.607 0.611 300AH-TOB 570.25 437.76 132.49 0.057 0.652 0.747 500AH-TOB 539.15 421.21 117.94 0.05 0.651 0.734 700AH-TOB 440.18 337.93 102.25 0.043 0.514 0.576 SBET: Specific surface area;
Smicro: Micropores specific surface area by t-plot method;
Sexternal：External surface area by t-plot method
Vt: Total pore volume;
Vmicro：Microporous volume by t-plot method
Vmeso：Mesopore volume
下载: 导出CSV
表 3 ST等温吸附模型拟合参数
Table 3. Isotherm parameters of ST adsorption on 300AHTOB
T/K Freundlich Langmuir Kf 1/n R2 b(L·mg−1) qm/(mg·g−1) R2 298 3.85 0.41 0.953 0.14 22.57 0.970 308 3.03 0.42 0.949 0.09 20.53 0.989 318 2.94 0.31 0.765 0.08 14.82 0.978
下载: 导出CSV
表 4 CV等温吸附模型拟合参数
Table 4. Isotherm parameters of CV adsorption on 300AHTOB.
T/K Freundlich Langmuir Kf 1/n R2 b(L·mg−1) qm(mg·g−1) R2 298 7.52 0.19 0.821 0.26 18.66 0.902 308 6.02 0.33 0.951 0.13 27.73 0.968 318 7.13 0.34 0.797 0.08 38.41 0.986
下载: 导出CSV
-
[1] 廖雯丽.锆渣制备硅酸钙绝热材料的研究[D].南京: 南京理工大学, 2007. [2] HEDDLE M F. Preliminary notice of substances which may prove to be new minerals[J]. Mineralogical Magazine and Journal of the Mineralogical Society, 1880, 4(18): 117-123. doi: 10.1180/minmag.1880.004.18.04 [3] TAYLOR H F W. Crestmoreite and riversideite[J]. Clay Minerals, 1953, 30(222): 155-165. [4] CLARINGBULL G F, HEY M H. A re-examination of tobermorite[J]. Mineralogical Magazine and Journal of the Mineralogical Society, 1952, 29(218): 960-962. [5] BIAGIONI C, BONACCORSI E, MERLINO S, et al. New data on the thermal behavior of 14Å tobermorite[J]. Cement and Concrete Research, 2013, 49(Complete): 48-54. [6] MITSUDA T. Paragenesis of 11Å tobermorite and poorly crystalline hydrated magnesium silicate[J]. Cement & Concrete Research, 1973, 3(1): 71-80. [7] MAESHIMA T, NOMA H, SAKIYAMA M, et al. Natural 1.1 and 1.4 nm tobermorites from Fuka, Okayama, JapanSi NMR and thermal behavior[J]. Cement & Concrete Research, 2003, 33(10): 1515-1523. [8] MERLINO S, BONACCORSI E, ARMBRUSTER T. The real structure of tobermorite 11Å: normal and anomalous forms, OD character and polytypic modifications[J]. European Journal of Mineralogy, 2001, 13(3): 577-590. doi: 10.1127/0935-1221/2001/0013-0577 [9] 何光辉, 孙俊民, 魏小芬, 等. 粉煤灰综合利用过程中斜托勃莫来石晶体化学行为研究[J]. 人工晶体学报, 2015, 44(09): 2379-2384. doi: 10.3969/j.issn.1000-985X.2015.09.011 [10] GARD J A. A further investigation of tobermorite from Loch Eynort, Scotland[J]. Mineralogical Magazine, 1957, 31(236): 361-370. doi: 10.1180/minmag.1957.031.236.03 [11] Eℓ-HEMALY S A S, MITSUDA T, TAYLOR H F W. Synthesis of normal and anomalous tobermorites[J]. Cement & Concrete Research, 1977, 7(4): 429-438. [12] 鲍梦燕, 郭晓潞, 施惠生. 水热合成托贝莫来石晶须及其耐高温性能的研究进展[J]. 功能材料, 2017, 48(11): 11075-11080. [13] 吕松青, 马淑花, 郭曦尧, 等. 粉煤灰动态水热合成纳米复合托贝莫来石晶须及其表征[J]. 过程工程学报, 2014, 14(03): 487-492. [14] GUO X, SONG M. Micro-nanostructures of tobermorite hydrothermal-synthesized from fly ash and municipal solid waste incineration fly ash[J]. Construction and Building Materials, 2018, 191: 431-439. [15] 李光辉, 张吉清, 罗骏, 等. 硅酸钠溶液合成托贝莫来石晶须[J]. 硅酸盐学报, 2012, 40(012): 1721-1727. [16] 赵秦仪, 王志增, 许欣, 等. 托贝莫来石晶体结构、热行为与合成研究现状[J]. 硅酸盐学报, 2020, 48(10): 1-16. [17] 张晓华, 邢宝恒. 以废混凝土做再生粗骨料配制混凝土探索试验[J]. 混凝土, 2010(11): 98-100. [18] 胡彪. 利用废弃加气混凝土制备硅酸钙绝热材料[D]. 南京: 南京理工大学, 2015. [19] 于方圆, 周莉, 何妍, 等. 离子液体修饰的三蝶烯多孔材料用于去除水溶液中阴离子染料[J]. 华东理工大学学报(自然科学版), 2020, 46(02): 155-163. [20] 王云辉, 牟广宇, 魏清莲, 黄永民. 多孔氧化铝的制备及其对酸性品红的吸附性能[J]. 华东理工大学学报(自然科学版), 2015, 41(05): 643-651. doi: 10.3969/j.issn.1006-3080.2015.05.011 [21] 姚炜屹, 王际童, 乔文明, 等. 活性炭纤维孔结构和表面含氧官能团对甲醛吸附性能的影响[J]. 华东理工大学学报(自然科学版), 2019, 45(5): 697-703. [22] 杨秀丽, 崔晓昱, 崔崇, 等. 托贝莫来石晶体的高温相变规律研究[J]. 光谱学与光谱分析, 2013(8): 2227-2230. doi: 10.3964/j.issn.1000-0593(2013)08-2227-04 [23] TANG X L, CUI C, CUI X Y, et al. High-temperature phase transition and the activity of tobermorite[J]. Journal of Wuhan University of Technology-Mater. Sci. Ed, 2014, 29(2): 298-301. [24] BIAGIONI C, BONACCORSI E, LEZZERINI M, et al. Thermal behaviour of Al-rich tobermorite[J]. European Journal of Mineralogy, 2016, 28(1): 23-32. doi: 10.1127/ejm/2015/0027-2499 [25] ZHAO Q, LI T, CUI C, et al. Preparation of porous silica powder via selective acid leaching of calcined tobermorite[J]. Powder Technology, 2020, 375: 420-432. doi: 10.1016/j.powtec.2020.08.008 -
点击查看大图
计量
- 文章访问数: 278
- HTML全文浏览量: 281
- PDF下载量: 4
- 被引次数: 0
