The thesis has found a new method to increase the pore size of mesoporous carbon by filling the liquid glass into the pore of the template (silica SBA-15) before impregnating the carbon presource to limit the penetration of carbon sealed the pore system of SBA-15. Stability of mesoporous carbon is increases due to silicon are partially retained in materials. This technique opens the way of synthesis of mesoporous carbon as an adsorbent with a desired pore size and stability.
MINISTRY OF EDUCATION VIETNAM ACADEMY OF AND TRAINING SCIENCE AND TECHNOLOGY GRADUATE UNIVERSITY OF SCIENCE AND TECHNOLOGY NGUYEN THI HONG HOA STUDY ON SYNTHESIS, CHARACTERISTICS AND ADSORPTION PROPERTIES OF TOXIC ORGANIC SUBSTANCES IN THE WATER ENVIRONMENT OF MESOPOROUS CARBON MATERIALS Major: Theoretical Chemistry and Physical Chemistry Code : 62.44.01.19 SUMMARY OF CHEMISTRY DOCTORAL THESIS Ha Noi – 2019 The work was completed at: Graduate Universty of Science and Technology - Vietnam Academy of Science and Technology Science supervisor 1: Assoc.Prof.Dr Dang Tuyet Phuong Science supervisor 2: Dr Tran Thi Kim Hoa Reviewer 1: … Reviewer 2: … Reviewer 3: … The thesis will be defended in front of doctoral thesis, held at the Graduate University Science and Technology - Vietnam Academy of Science and Technology at o’clock, on day month year 2019 Thesis can be found at: - Library of the Graduate University Science and Technology - National Library of Vietnam INTRODUCTION The necessity of the thesis Mesoporous carbon materials have an ordered structure, uniform pore size They often were synthesized by two methods: soft-templating and hard-templating With the soft-templating method, materials have been prepared via self-assembly by using soft-templating (surfactant) The obtained materials have less orderly structure The pore size of the material is difficult to control and the template is difficult to remove With the hard-templating method, MCM-48, SBA-15, etc are used as the templates The materials have highly order structure, uniform and easily controlled pore size Therefore, hard-templating method is used more widely However, the pore size of materials is smaller than that of the hard-templates because obtained materials are inverse copies of the templates The thickness of the wall and the pore size are limited by size and shape form of hard-templates So far, the pore size of mesoporous carbon materials are synthesized by hard-templating method only reach the maximum of ~ 5.5 nm The increasing in pore size is not feasible because it is limited by the size of the templates, resulting in framework collapse and pore breakage due to decrease stability Hence, it is necessary to find new methods to synthesize mesoporous carbon materials with larger sizes, higher stability Mesoporous carbon materials are said to be a good adsorbent of organic substances in water environment However, these materials are not stability The structure of the materials is easily broken during the reuse process and it is difficult to recover So, the regeneration and reuse of mesoporous carbon materials are very difficult Because of, if heat is used to remove completely adsorbed, it is necessary to perform high temperature causing to burn mesoporous carbon materials Also, the solvents are used to remove the adsorbed, resulting less-economical effect and secondary pollution Therefore, the research to find the effective and feasible methods for regeneration and reuse of mesoporous carbon materials is necessary From the above reasons, the thesis topic “Study on synthesis, characteristics, and adsorption properties of toxic organic substances in the water environment of mesoporous carbon materials” was studied The purpose of the thesis Study on control the process of synthesizing mesoporous carbon materials with an ordered structure, large pore size, high stability They are as an effective adsorbent for toxic organic substances with different molecular sizes in water environment Synthesis of mesoporous carbon materials with desired order structure, large pore size, high durability for effective adsorption of different molecular size toxic organic substances in water environment Scientific and practical significance of the thesis The thesis has found a new method to increase the pore size of mesoporous carbon by filling the liquid glass into the pore of the template (silica SBA-15) before impregnating the carbon presource to limit the penetration of carbon sealed the pore system of SBA-15 Stability of mesoporous carbon is increases due to silicon are partially retained in materials This technique opens the way of synthesis of mesoporous carbon as an adsorbent with a desired pore size and stability Doping iron into the framework of mesoporous carbon materials creates catalysts to decompose adsorbed, release the adsorption sites, regeneration and reuse of mesoporous carbon, extend the scope of application of materials for treatment of toxic organic substances in water New findings of the thesis For the first time, a new technique is used to control the pore size of the mesoporous carbon materials which is synthesized by hard – temlating method by filling the liquid glass into the pore of SBA-15 before impregnating the carbon source to prevent penetration carbon to seal the pore system of SBA-15 This technique opens new direction for mesoporous carbon synthesis technologies as the adsorbent with the desired pore size Retaining a silicon part in synthesiszed material to increase the stability of the mesoporous carbon material Using atom-planting method to put iron into framework of the mesoporous carbon material not change the structure of the materials Iron exists on the surface of materials in the highly dispersed Fe2O3 and FeO forms, favorable for adsorption and decomposition of methylene blue, enhance the ability of regeneration, reuse and not cause secondary pollution The structure of the thesis The thesis consists of 140 pages with 83 figures, 31 tables The thesis includes the following sections: Introduction (2 pages); Chapter 1: Overview (44 pages); Chapter 2: Research methods and experiment (16 pages); Chapter 3: Results and discussion (59 pages); Conclusions(2 pages); Novel scientific contributions of the thesis; List of publications; References and appendices CHAPTER OVERVIEW Chapter includes a general introduction of synthesis methods, application of mesoporous carbon materials and metal containing mesoporous carbon Mesoporous carbon materials are synthesized by two methods: soft-templating and hard-templating Metal containing mesoporous carbon materials are synthesized by two methods: impregnation and atom-planting In this chapter, adsorption properties, application and adsorption mechanism of mesoporous carbon materials in the field of adsorption were introduced CHAPTER RESEARCH METHODS AND EXPERIMENT 2.1 Chemistry - F127 (Sigma-Aldrich); Phenol (China); Focmaldehit (China); SBA15, MCF (Synthesis from liquid glass - Department of Surface Chemistry - Institute of Chemistry - Vietnam Academy of Science and Technology); Refined sugar (Vietnam); Liquid glass (Vietnam) 2.2 Synthesis of materials 2.2.1 Synthesis of mesoporous carbon - Soft–templating method: Template F127; pH = 1, 2, 3; Temperature: 80 oC, 100 oC, 120 oC - Hard-templating method: Templates of SBA-15 or MCF; Number of impregnations: 1, 2, 3; Figure 2.3 Process of synthesizing mesoporous carbon The CMQTBC(TTL) pattern is synthesized using a hard-templating method, but the liquid glass is filled into the pore of SBA-15 before impregnating the carbon source Table 2.2 Samples of mesoporous carbon Materials Method CMQTBM1 T (oC) N1 Templating N2 100 - F127 - 100 - F127 - 100 - F127 - 80 - F127 - CMQTBM120 120 - F127 - CMQTBC1(SBA-15) - - SBA-15 CMQTBC2(SBA-15);CMQTBC(SBA-15) - - SBA-15 - - SBA-15 - - MCF - - SBA-15 - - SBA-15 - - SBA-15 CMQTBM2; CMQTBM100 Soft- CMQTBM3 templating CMQTBM80 CMQTBC3(SBA-15) Hard- CMQTBC(MCF) templating CMQTBC(TTL) Fe-t-CMQTBC(TTL) (Impregnation) Fe-b-CMQTBC(TTL) (Atom-planting) pH 2 Temperature; Number of impregnation; Number of g Na2SiO3 2.2.2 Synthesis of iron containing mesoporous carbon - Synthesis of Fe-t-CMQTBC(TTL) by impregnating iron nitrate 0.2 M (6% mass of Fe) - Synthesis of Fe-b-CMQTBC(TTL) by the atom-planting method 2.3 Characterizations - Characterization techniques: XRD, SEM, TEM, BET, EDX, TA, FTIR, XPS 2.4 Determination of the isoelectric point of mesoporous carbon 2.5 Determination of adsorption properties Langmuir, Freundlich adsorption isotherm models The pseudo-fisrt-order and pseudo-second-order adsorption kinetic models 2.6 Method of evaluating the ability to reuse materials Recover the material after adsorption and wash with water and ethanol + methanol (methanol and ethanol 1: ratio, V = 60 ml) stir for hours at 60 ° C Then, the material is used to adsorb MB CHAPTER RESULTS AND DISCUSSION 3.1 Synthesis of mesoporous carbon 3.1.1 Soft-templating method *) Effect of temperature 80 oC, 100 oC, 120 oC: Figure 3.1; 3.2 XRD patterns (A) and nitrogen adsorptiondesorption isotherms (B) of mesoporous carbon are synthesized at different temperatures Temperature increase → Brown motion increases → Selfassembly of surfactants increase → The length of the hydrophobic chain increases → pore size increases Temperature high (over 100 C) → evaporate water, flocculate surfactants → pore size decreases o So, the optimal synthetic temperature is 100 oC *) Effect of pH = 1, 2, 3: Figure 3.5; 3.6 XRD patterns (A) and Nitrogen adsorptiondesorption isotherms (B) of CMQTBM1, CMQTBM2 and CMQTBM3 The zero charge point of silicon is 2, if pH = 2, mesoporous carbon materials are formed according to the correct mechanism S0H+X− I (S: F127, X− Cl−; I: Si) Thus, conditions of suitable syntheting of materials are at 100 °C and pH = 2, the obtained materials have a mesoporous structure with pore size of 5.4 nm, surface area BET of 1693 m2/g 3.1.2 Hard-templating method 3.1.2.1 Templating: using two templating with the same hexagonal structure, but the pore size of MCF is larger than that of SBA-15 Figure 3.9; 3.10 XRD patterns of SBA-15; CMQTBC(SBA-15) (A) and MCF; CMQTBC(MCF) (B) XRD pattern shows that the structure of CMQTBC(SBA-15) and CMQTBC(MCF) is similar to that of SBA-15 and MCF Figure 3.11 TEM images of CMQTBC(SBA-15) and CMQTBC(MCF) The structure of CMQTBC(SBA-15) and CMQTBC(MCF) samples have a hexagonal structure and uniform pore size (Figure 3.11 and 3.12) The pore size of CMQTBC(MCF) is larger than that of CMQTBC(SBA-15) because of the pore size of MCF is larger than that of SBA-15 Figure 3.12 Nitrogen adsorptiondesorption isotherms CMQTBC(SBA15) and CMQTBC(MCF) Figure 3.12 shows that both CMQTBC(SBA-15) and CMQTBC(MCF) belong to type IV isotherm with a hysteresis The pore sizes of CMQTBC(SBA-15) and CMQTBC(MCF) are in the range of respectively 4.2 nm; 5.6 nm Figure 3.13 TGA patterns of CMQTBC(SBA-15) (A) and CMQTBC(MCF) (B) 12 area SBET and porosity Vpore increase to 1276 cm3/g and 4.304 cm3/g respectively because silicon was further removed, causing the expanding of pore, increasing in the average pore volume but the structure is less stable and the signs of structural collapse occur (Figure 3.21) Figure 3.21 SEM images of CMQTBC(TTL) and C5 Figure 3.23 TGA pattern of Figure 3.24 XPS spectra of CMQTBC(TTL) Figure 3.23 CMQTBC(TTL) shows that CMQTBC(TTL) (complete o combustion temperature of 605 C) has higher thermal stability than CMQTBC(SBA-15) (559 oC) XPS spectra (Figure 3.24) show the peaks at the energy level of 103 eV; 285 eV; 530 eV which are assigned to the presence of Si2p; C1s, O1s in CMQTBC(TTL) materials Thus, with the technique of using pore-filled liquid glass SBA-15, synthesized MC material with large pore size (10.4 nm), surface area (772 m2/g) and high pore volume (1.603 cm3/g) Sumary: For soft-templating method: conditions of suitable synthetic materials are at 100 oC, pH = The obtained materials have a 13 mesoporous structure with a pore size of 5.4 nm, porous characteristics, and BET surface area of 1693 m2/g The order of materials is not high For hard-templating method: - Suitable conditions for synthesizing materials: SBA-15 is template and number of impregnation is 2; - It is possible to change the pore size of materials by using different templates with different pore sizes such as SBA-15 and MCF - filling the liquid glass into the pore of SBA-15 before impregnating the carbon source to prevent penetration carbon to seal the pore system of SBA-15 resulting the adsorbent with the desired pore size.is a new technique that has never been reported in the literature - Stability of the mesoporous carbon materials increases due to retaining a part of silicon in the material 3.2 Synthesis of iron containing mesoporous carbon Figure 3.25 XRD patterns of Fe-t-CMQTBC(TTL) and Fe-bCMQTBC(TTL)( small corners) Figure 3.26 XRD patterns of Fe-t-CMQTBC(TTL) and Fe-bCMQTBC(TTL) (large corners) 14 XRD patterns (Figure 3.25) show that the structure of Fe-tCMQTBC(TTL) and Fe-b-CMQTBC(TTL) is similar to that of CMQTBC(TTL) (Figure 3.16), demonstrating that doping iron into the material does not affect the structure of the material Figure 3.26 shows that Fe-t-CMQTBC(TTL) material does not have characteristic peak for iron on the material, may be small iron content below the detection threshold of XRD method or exists amorphous form Fe-b-CMQTBC(TTL) has peaks with a value of 2θ in accordance with the standard data for the structure of Fe 2O3 This shows that with the atomic implant method, iron exists the form of oxide on mesoporous carbon TEM images (Figure 3.27) show that the doping Fe does not change the structure of mesoporous carbon material and highly disperses iron Figure 3.28 FTIR spectra of CMQTBC(TTL), Fe-t- CMQTBC(TTL) and Fe-tCMQTBC(TTL) FTIR spectra (Figure 3.28) show the existence of –OH, C–H, -C=C, -C=O, and -C–O groups in structure of CMQTBC(TTL), Fe-tCMQTBC(TTL) and Fe-b-CMQTBC(TTL) With iron containing samples (Fe-t-CMQTBC(TTL) and Fe-b-CMQTBC(TTL)) have additional peaks at 457.13 435.91 cm-1 assigned to peak of the link Fe–O 15 Figure 3.29 Nitrogen adsorptiondesorption isotherms of Fe-tCMQTBC(TTL) and Fe-bCMQTBC(TTL) Figure 3.29 shows that Fe-t-CMQTBC(TTL) Fe-bCMQTBC(TTL) materials have the same structure with the surface areas of 749 m2/g 542 m2/g respectively, lower than that of CMQTBC(TTL) (772 m2/g), consistent with XRD data The pore size of Fe-t-CMQTBC(TTL) is smaller than that of Fe-bCMQTB(CTTL) which may be due to the pore partially covered the by iron oxide Figure 3.30 shows the existence of element Fe in Fe-tCMQTBC(TTL) and Fe-b-CMQTBC(TTL) with the percentage of 4,63% and 6,20%, respectively XPS spectra (Figure 3.31) show the occurrence of peaks at the energy level 103 eV; 285 eV; 530 eV; 711 eV assigned to the presence of Si2p; C1s, O1s and Fe2p in Fe-t-CMQTBC(TTL) and Fe-b-CMQTBC(TTL) The peaks of Fe-t-CMQTBC(TTL) has peaks at 710.5 eV and 724 eV corresponding to Fe2O3 Fe2p3/2 and Fe2p1/2 structures, is not only the same Fe-b-CMQTBC(TTL) but also two peaks with a small intensity at 720 eV and 714 eV This may be due to the process formation of CO at high temperatures (400-500 oC) which reduced Fe3+ to lower valence iron such as Fe2+ 16 Figure 3.31 XPS spectra of Fe-t-CMQTBC(TTL) and Fe-bCMQTBC(TTL) a: Total spectra, b: Fe2p In addition, on the Fe-b-CMQTBC(TTL) spectra C1s (not shown here), there is also the appearance of the peak with power level at 291 eV This is because the process of introducing iron at high temperatures has resulted in the process of breaking carbon creating many π-π * bonds of the material Sumary: The addition of iron by the atom-planting method is superior to the impregnation method: iron oxide particle is highly dispersed on the CMQTBC(TTL) material There is the formation of a new iron state Fe2+ and the π-π bond in the structure of Fe-b-CMQTBC(TTL) material is increased, the pore size is almost unchanged 3.3 Evaluation of adsorption capacity of mesoporous carbons 3.3.1 Affecting factors Survey of factors: different adsorbents (MB and RhB), initial concentrations and pH showed that the adsorption capacity of MB, RhB on CMQTBC(SBA-15) is nearly the same, due to the surface area and the pore size of CMQTBC(SBA-15) is larger than the size of MB and RhB MB adsorption capacity on CMQTBC(SBA-15), CMQTBC(TTL) increases when the initial MB concentration in the solution increases and it is possible to use mesoporous carbon adsorption MB in pH = suitable to actual conditions, because the 17 isoelectric point of CMQTBC(SBA-15) and CMQTBC(TTL) has values of 5.5 and 5.7 respectively 3.3.2 Study of the adsorption isotherm Table 3.10, 3.11 Langmuir, Freundlich adsorption isotherm parameters describe MB adsorption process on CMQTBC(SBA-15),CMQTBC (TTL) Model Langmuir Material CMQTBC(SBA-15) CMQTBC(TTL) qm (mg/g) 398,41 476,19 KL (L/mg) 1,4022 0,4375 R 0,9992 0,9999 RL 0,00038 – 0,00077 0,00455 – 0,02235 R2 0,6394 0,7863 n 9,4697 6,7935 KF (mg/g) 286,00 233,41 Freundlich MB adsorption on CMQTBC(SBA-15), CMQTBC(TTL) materials obeys to the Langmuir isothermal model The maximum MB adsorption capacity (qm, mg/g) on CMQTBC(TTL) is 476.19 mg/g, greater than on CMQTBC(SBA-15) of 398.41 mg/g, due to the large pore size of CMQTBC(TTL) makes the MB molecule easy to adsorb, in addition to the presence of surface functional groups as well as π-π bonds during MB adsorption on these materials and electrostatic interaction between the surface of material and adsorbent 3.3.3 Study adsorption kinetics Table 3.13, 3.14 show that the pseudo-second-order kinetic equation is fitted to the adsorption process MB on CMQTBC(SBA15), CMQTBC(TTL) 18 Table 3.13, 3.14 Kinetic parameters for pseudo-fisrt-order and pseudo-second-order kinetic equations of adsorption process on CMQTBC(SBA-15) and CMQTBC(TTL) Co (mg/L) R12 k1 (1/ q1e, cal qe, exp min) (mg/g) (mg/g) R22 k2 q2e,cal (g/(mg.min)) (mg/g) v0 (mg/(g.min)) CMQTBC(SBA-15) 100 0,2869 0,0232 0,55 166,57 0,0450 166,67 1250 150 0,8871 0,0329 12,10 249,84 0,0047 250,00 294 200 0,9841 0,0183 43,56 332,58 0,0011 333,33 122 CMQTBC(TTL) 100 0,3128 0,0097 0,37 197,58 0,2601 196,08 10000 150 0,6622 0,0082 10,15 291,77 0,0050 294,12 433 200 0,4842 0,0043 9,06 386,54 0,0097 384,62 1435 R1 , R2 , k1, k2, q1e,cal, q2e,cal are correlation coefficient, the rate constant, adsorption capacity calculated according to pseudo-first-order and pseudo-second-order kinetic equations, respectively; v0: start adsorption rate 19 3.4 Evaluation of adsorption capacity of mesoporous carbons containing iron 3.4.1 Study of isotherm adsorption Table 3.16, 3.17 Langmuir, Freundlich adsorption isotherm parameters describe MB adsorption process on Fe-t- CMQTBC(TTL), Fe-b-CMQTBC(TTL) Model Fe-t- Fe-b- CMQTBC(TTL) CMQTBC(TTL) qm (mg/g) 625,00 1428,57 KL (L/mg) 0,4324 1,4000 R2 0,9987 0,9525 RL Material Langmuir Freundlich 0,00575 – 0,02795 0,000178 - 0,00709 R 0,9832 0,9423 1/n 8,4459 3,6697 KF (mg/g) 358,43 727,34 The adsorption process of MB on Fe-t-CMQTBC(TTL), Feb-CMQTBC(TTL) well obeys to the Langmuir adsorption isotherm model than the Freundlich adsorption isotherm model (Table 3.16, 3.17) Maximum MB adsorption capacity qm of Fe-t- CMQTBC(TTL) and Fe-b-CMQTBC(TTL) is higher than that of CMQTBC(TTL) because it is affected by the same factors as with CMQTBC(TTL) and affected by the complexing ability of iron with MB (Figure 3.46) and MB oxidation ability of active iron sites Maximum MB adsorption capacity qm of Fe-b-CMQTBC(TTL) is higher than that of Fe-b-CMQTBC(TTL) because The iron in the Feb-CMQTBC(TTL) is better dispersed, contains low valence iron sites so it has the ability to oxidize MB and contain more π-π bonds 20 Table 3.18, 3.19 Kinetic parameters for pseudo-fisrt-order and pseudo-second-order kinetic equations of of adsorption process on Fe-t-CMQTBC(TTL) and Fe-b-CMQTBC(TTL) Co (mg/L) R12 k1 (1/ q1e, cal qe, exp min) (mg/g) (mg/g) R22 k2(g/(mg q2e,cal v0 min)) (mg/g) (mg/(g min)) Fe-t-CMQTBC(TTL) 150 0,7491 0,1809 74,26 475,95 0,9997 0,0049 476,19 1111 200 0,7864 0,1447 37,32 546,95 0,9999 0,0108 555,56 3333 300 0,9303 0,1889 53,01 615,17 0,0085 625,00 3320 Fe-b-CMQTBC(TTL) 150 0,9694 0,0144 3,66 498,38 0,0200 500 5000 200 0,9614 0,0096 7,04 663,67 0,0075 666,67 3333 300 0,9150 0,0084 16,48 989,30 0,0050 1000 5000 R1 , R2 , k1, k2, q1e,cal, q2e,cal are correlation coefficient, the rate constant, adsorption capacity calculated according to pseudo-first-order and pseudo-second-order kinetic equations, respectively; v0: start adsorption rate 21 Figure 3.46 MB adsorption mechanism on carbon mesoporous (MC) adsorbent 3.4.2 Study adsorption kinetics Table 3.18, 3.19 show that the pseudo-second-order kinetic equation is fitted to the adsorption process MB on Fe-t- CMQTBC(TTL), Fe-b-CMQTBC(TTL) 3.5 Evaluate the regeneration capacity of mesoporous carbon Figure 3.54 MB adsorption performance on materials: a) CMQTBC(TTL), b) Fe-t- CMQTBC(TTL) and c) Fe-b-CMQTBC(TTL) Adsorption efficiency after reuse of CMQTBC(TTL) decreased significantly from 95.01% to 74.34% after times of use For Fe-t-CMQTBC(TTL) over four times of reuse, MB adsorption efficiency slightly decreased to 96.31%, 94.23%, 93.86% and 83.90%, respectively For Fe-b-CMQTBC(TTL), it can be seen that after four times of reuse, adsorption efficiency has not decreased by almost 99.47% This can be explained by the fact that the iron nano-oxide is highly dispersed on the surface of the material, increasing the 22 degradation process of the adsorbed MB, quickly releasing the adsorption sites for reuse Hình 3.55, 3.56 XRD pattern (A) TEM image (B) of Feb-CMQTBC(TTL) after times of reuse Figures 3.55 and 3.56 show that the state of iron oxide and material structure is not significantly changed after times of reuse 3.6 Initial assessment of the catalytic ability of iron containing mesoporous carbon Figure 3.57, 3.58 Kinetic line when giving 0.03 g of material Fe-t-CMQTBC(TTL) (a), Fe-b-CMQTBC(TTL) (b) in 100 ml MB solution 300 mg/L at temperature 250C The ability to remove MB of Fe-t-CMQTBC(TTL) and Fe-bCMQTBC(TTL) two materials with H2O2 is better than without H2O2, proves that iron is the catalytic activity for MB decomposition process In particular, Fe-b-CMQTBC(TTL) showed the highest activity, when H2O2 was present, MB concentration decreased rapidly and almost zero after 40 minutes (Figure 3.58) Rapid decomposition capacity MB is due to Fe-b-CMQTBC (TTL) containing Fe2+ catalytic sites (XPS spectrum) accelerating MB oxidation when H2O2 is present 23 Conclusion Carbon mesoporous were successfully synthesized by two methods: - Soft-templating method: Using soft-template F127, suitable synthesis conditions: 100 oC, pH = The obtained material has a mesoporous structure with low order, the pore size of 5.4 nm, BET surface area of 1693 m2/g - Hard-templating method: Using two hard-templates: SBA15 and MCF Using the SBA-15, obtained materials have smaller pore size (4.2 nm) and higher thermal stability (595 oC) than that of using MCF (5.6 nm and 552 oC) When using SBA-15, suitable amount of carbon precusor (sucrose) for impregnation is times and g of sucrose for each time Finding the new technique to synthesize CMQTB materials by hard mold method is to fill liquid glass into the pore of SBA-15 template before impregnating carbon source to limit the penetration of carbon to seal the pore system of SBA-15, increased the pore size of the material from 4.2 nm (without liquid glass) to 10.4 nm (with liquid glass) In addition, retaining a part of silicon in the material increased the stability of the CMQTB materials (thermal stability at 605oC) is a new idea in the field of synthesizing mesoporous carbon materials Iron containing CMQTBC(TTL) materials were synthesized by two methods: impregnation and atom-planting With the impregnation method, iron exists in the form of amorphous iron oxide The atom-planting method is better than the impregnation method: iron exists in the form of highly dispersed Fe2O3 and FeO iron oxide, pore structure and pore size are almost unchanged 24 Investigation of MB adsorption on synthesized CMQTBC(SBA-15), CMQTBC(TTL), Fe-t-CMQTBC(TTL), Fe-bCMQTBC(TTL) materials showed that: - The adsorption isotherm of the samples well fit to the Langmuir isotherm model The adsorption kinetics obeys the pseudosecond-order kinetic model - Iron containing mesoporous carbon materials have a higher absorption capacity of MB than that of non-iron materials due to the catalytic decompositing MB of active iron sites Maximum MB adsorption capacity on materials is order: CMQTBC(SBA-15) (398.41 mg/g) < CMQTBC(TTL) (476.19 mg/g) < Fe-t- CMQTBC(TTL) (625.00 mg/g) < Fe-b-CMQTBC(TTL) (1428.57 mg/g) - Maximum MB adsorption capacity of Fe-b-CMQTBC(TTL) prepared by atom-planting method is times higher than that of (Fe-tCMQTBC)(TTL) prepared by impregnation method due to an increase in π-π bond in Fe-b-CMQTBC(TTL) which have a strong affinity for aromatic ring of MB, and the formation of Fe2+ iron promoted the generation of free radicals OH• participating in MB decomposition reaction Evaluation of the reuse ability of the iron-containing materials (Fe-t-CMQTBC(TTL) and Fe-b-CMQTBC(TTL)) showed that: Iron plays a role as catalytic sites for decomposition of adsorbed MB, increases the ability to reuse materials MB adsorption efficiency after times of regeneration of Fe-b-CMQTBC(TTL) (99.47%) is higher than that of Fe-t-CMQTBC(TTL) (83.90%) which is explained by the existence of highly dispersed iron oxide and Fe2+ catalytic sites on the surface of the material, easily decomposing adsorbed MB, quickly releasing adsorption sites for reuse 25 LIST OF WORKS HAS BEEN PUBLISHED [1] Đào Đức Cảnh, Nguyễn Thị Nhường, Nguyễn Thị Hồng Hoa, Lê Hà Giang, Nguyễn Kế Quang, Nguyễn Trung Kiên, Trần Thị Kim Hoa, Vũ Anh Tuấn, Đặng Tuyết Phương Tổng hợp, đặc trưng nghiên cứu động học hấp phụ xanh metylen vật liệu cacbon mao quản trung bình trật tự Tạp chí xúc tác hấp phụ, T.3 (4), 33 – 38, 2014 [2] Đào Đức Cảnh, Nguyễn Thị Nhường, Nguyễn Thị Hồng Hoa, Lê Hà Giang, Nguyễn Kế Quang, Nguyễn Trung Kiên, Trần Thị Kim Hoa, Vũ Anh Tuấn, Đặng Tuyết Phương Nghiên cứu tính chất hấp phụ xanh metylen vật liệu cacbon mao quản trung bình chứa đồng Tạp chí Hóa học, 52 (6A), 163 – 167, 2014 [3] Nguyễn Thị Hồng Hoa, Đào Đức Cảnh, Nguyễn Thị Hà, Lê Hà Giang, Nguyễn Kế Quang, Nguyễn Trung Kiên, Trần Thị Kim Hoa, Vũ Anh Tuấn, Đặng Tuyết Phương Tổng hợp vật liệu cacbon mao quản trung bình đánh giá khả hấp phụ xanh metylen vật liệu Tạp chí Khoa Học Cơng nghệ - Đại học Thái Nguyên, 14(13)/3, 139 – 143, 2015 [4] Đào Đức Cảnh, Nguyễn Thị Hồng Hoa, Lê Hà Giang, Nguyễn Kế Quang, Nguyễn Trung Kiên, Trần Thị Kim Hoa, Vũ Anh Tuấn, Đặng Tuyết Phương Comparison of MB adsorption capacity on OMCs synthesized by hard template and soft template methods Proceeding of IWNA 2015, 11-14 November, Vung Tau, Vietnam, 517 – 521, 2015 [5] Nguyễn Thị Hồng Hoa, Đào Đức Cảnh, Lê Hà Giang, Nguyễn Kế Quang, Nguyễn Trung Kiên, Trần Thị Kim Hoa, Vũ Anh Tuấn, Đặng Tuyết Phương Synthesis of ordered mesoporous carbons (OMCs) with improved pore structure Proceeding of IWNA 2015, 11-14 November, Vung Tau, Vietnam, 356 – 359, 2015 26 [6] Phuong T Dang, Hoa T H Nguyen, Canh D Dao, Giang H Le, Quang K Nguyen, Kien T Nguyen, Hoa T K Tran, Tuyen V Nguyen, and Tuan A Vu Ordered Mesoporous Carbons as Novel and Efficient Adsorbent for Dye Removal from Aqueous Solution Advances in Materials Science and Engineering, vol 2016, 1-9, 2016 [7] Nguyễn Thị Hồng Hoa, Trần Thị Kim Hoa, Đặng Tuyết Phương Ảnh hưởng pH đến cấu trúc tính chất hấp phụ xanh metylen vật liệu cacbon mao quản trung bình Tạp chí Xúc tác Hấp phụ, T5 (No4), 120 – 123, 2016 [8] Nguyễn Thị Hồng Hoa, Trịnh Thị Thu Hường, Đào Đức Cảnh, Lê Hà Giang, Nguyễn Kế Quang, Nguyễn Trung Kiên, Trần Thị Kim Hoa, Vũ Anh Tuấn, Đặng Tuyết Phương Tổng hợp, đặc trưng khả phân hủy xanh metylen vật liệu cacbon mao quản trung bình chứa Fe Tạp chí Hóa học, 54(6e2), 94 – 98, 2016 [9] Nguyễn Thị Hồng Hoa, Trần Thị Kim Hoa, Đặng Tuyết Phương Synthesis of mesoporous carbon material by hard template method: Application to removal of dye from aqueous solution Tạp chí Khoa Học Công nghệ - Đại học Thái Nguyên, 172(12/1), 59 – 64, 2017 [10] Nguyễn Thị Hồng Hoa, Trần Thị Kim Hoa, Đặng Tuyết Phương Ảnh hưởng nhiệt độ đến cấu trúc tính chất hấp phụ xanh metylen vật liệu cacbon mao quản trung bình tổng hợp phương pháp mềm Tạp chí Xúc tác Hấp phụ, T6 – No4, 134 – 137, 2017 [11] Nguyễn Thị Hồng Hoa, Trần Thị Kim Hoa, Đặng Tuyết Phương Synthesis of mesoporous carbon material by hard template method: a comparative study of SBA-15 and MCF as templates Vietnam Journal of Catalysis and Adsorption, 7-issue 1, xxx-xxx, 2018 ... properties of toxic organic substances in the water environment of mesoporous carbon materials? ?? was studied The purpose of the thesis Study on control the process of synthesizing mesoporous carbon materials. .. reported in the literature - Stability of the mesoporous carbon materials increases due to retaining a part of silicon in the material 3.2 Synthesis of iron containing mesoporous carbon Figure... OVERVIEW Chapter includes a general introduction of synthesis methods, application of mesoporous carbon materials and metal containing mesoporous carbon Mesoporous carbon materials are synthesized by