Preparation of modified MXene material and its adsorption performance for Sr2+
-
摘要: 为了评估Ti3CNTx/TMAOH材料对模拟放射性废水中Sr2+的吸附性能,选用四甲基氢氧化铵(TMAOH)作插层剂,对其进行改性制备处理,优化产物Ti3CNTx/TMAOH的合成条件,并采用SEM-EDS、XRD、BET和FTIR等对改性前后的样品进行表征分析。序批式实验中考察了吸附剂Ti3CNTx/TMAOH的投加量、时间、pH和竞争离子等因素对除Sr2+效果的影响。结果表明:在投加量为1.0 g∙L−1、pH为6、时间为10 min时,对Sr2+的去除率可达99.28%。竞争离子的抑制顺序为Ca2+$ \text{ > > } $Mg2+$ \text{ > } $K+$ \text{ > } $Na+$ \text{ > } $Cs+。经历4次循环再生后,对Sr2+的去除率为69.56%。整个吸附过程符合准二级动力学模型,吸附等温线符合Redlich-Peterson (R-P)模型。在以自来水和湖水为背景配制的模拟含Sr2+废水中,可分别去除93.80%和68.49%的Sr2+。结合各种表征结果分析,表明Ti3CNTx/TMAOH对Sr2+优异的吸附机制可归因于离子交换、表面螯合、静电吸附和层间截留作用。Abstract: Ti3CNTx/TMAOH was prepared when tetramethylammonium hydroxide (TMAOH) was selected as the intercalating agent. Adsorption performance of Ti3CNTx/TMAOH on Sr2+ in simulated radioactive wastewater was evaluated. The synthesized Ti3CNTx/TMAOH was characterized by SEM-EDS, XRD, BET and FTIR. In the batch experiment, the effects of the dosage of adsorbent Ti3CNTx/TMAOH, time, pH and competitive ions on Sr2+ removal were investigated. The results show that the removal rate of Sr2+ is 99.28% when the dosage is 1.0 g·L−1, pH is 6, and the time is 10 min. The inhibition order of competitive ions is Ca2+$ \text{ > > } $Mg2+$ \text{ > } $K+$ \text{ > } $Na+$ \text{ > } $Cs+. After four adsorption-desorption cycles, the Sr2+ removal rate is 69.56%. The adsorption is consistent with the pseudo-second-order kinetic. The adsorption isotherm data conforms to the Redlich-Peterson (R-P) model. 93.80% and 68.49% Sr2+ can be removed in tap water and lake water, respectively. Sr2+ is adsorbed by Ti3CNTx/TMAOH via ion exchange, surface chelation, electrostatic adsorption and interlayer interception.
-
Key words:
- MXene /
- tetramethylammonium hydroxide /
- modified materials /
- adsorption /
- Sr2+
-
图 10 时间t对Ti3CNTx/TMAOH去除Sr2+的影响:(a) 吸附容量;(b) 去除率;(c) 准一级动力学模型;(d) 准二级动力学模型
Figure 10. Effect of contact time t on Sr2+ removal by Ti3CNTx/TMAOH: (a) Adsorption capacity; (b) Removal rate; (c) Pseudo-first-order kinetic model; (d) Pseudo-second-order kinetic model
qt—Adsorption capacity at time t; qe—Adsorption capacity at equilibrium time
表 1 Ti3CNTx和Ti3CNTx/TMAOH的比表面积、孔容和孔径数据
Table 1. Surface area, pore volume, and pore diameter of Ti3CNTx and Ti3CNTx/TMAOH
Material Surface
area/
(m2·g−1)Pore
volume/
(cm3·g−1)Pore
diameter/
nmTi3CNTx 1.215 0.0044 38.01 Ti3CNTx/TMAOH 3.154 0.0029 16.13 表 2 Ti3CNTx/TMAOH吸附Sr2+的动力学模型参数
Table 2. Parameters of adsorption kinetics model of Sr2+ adsorption on Ti3CNTx/TMAOH
Kinetic model 5.5 mg∙L−1 10 mg∙L−1 30 mg∙L−1 50 mg∙L−1 Pseudo-first-order qe/(mg∙g−1) 25.02 22.80 10.49 8.061 k1/(10−4 min−1) 0.01869 5.540 34.50 127.10 R2 0.1065 0.6222 0.6940 0.9302 Pseudo-second-order qe/(mg∙g−1) 4.988 8.829 24.16 29.83 k2/(g∙mg−1∙min−1) 0.1573 0.08457 0.01053 0.00587 R2 1.00 0.9986 0.9999 0.9998 Notes: k1 and k2—Reaction rate constants of pseudo-first-order and pseudo-second-order equations, respectively; R2—Correlation coefficient. 表 3 Ti3CNTx/TMAOH吸附Sr2+的吸附等温线拟合参数
Table 3. Fitting parameters of adsorption isotherm for Sr2+ on Ti3CNTx/TMAOH
T/℃ Langmuir Freundlich R-P qmax/(mg∙g−1) KL/(L∙mg−1) R2 KF/(mg∙g−1) n R2 A/(L∙g−1) B g R2 20 25.04 0.033 0.996 2.90 3 0.970 10.7 13 0.89 0.999 30 37.47 0.036 0.974 3.37 2 0.886 11.9 16 0.96 0.991 40 41.91 0.038 0.990 4.98 3 0.917 12.5 18 0.99 0.999 Notes: T—Reaction temperature; qmax—Maximum adsorption capacity of Langmuir; KL—Langmuir adsorption constant; KF—Freundlich adsorption constant; n—Constant related to the adsorption strength; A and B—Constants related to the adsorption capacity; g—Empirical constant between 0 and 1. 表 4 不同吸附剂对Sr2+的吸附去除效果对比
Table 4. Comparison of adsorption and removal effects of different adsorbents for Sr2+
Adsorbents qmax/(mg∙g−1) C0/(mg∙L−1) t/min pH Ref. MnxOy-SbmOn 30.20 4.4 ~30 3.0-9.0 [25] ZrO2-MnO2 30.86 100 ~100 4.0-8.0 [26] GO 23.83 7.4 — 6.5-11.0 [27] M/GO 9.81 4.0 360 1.7-11.8 [28] Commercial AC 7.58 50 — 8.0-11.0 [29] Ti3CNTx/TMAOH 41.91 5.5 ~120 5-11 This study Notes: t—Adsorption equilibrium time; GO—Graphene; M—Ge, Sn; AC—Activated carbon. 表 5 Ti3CNTx/TMAOH吸附Sr2+的热力学参数
Table 5. Thermodynamic parameter for adsorption Sr2+ on Ti3CNTx/TMAOH
ΔG/(kJ∙mol−1) ΔH/
(kJ∙mol−1)ΔS/
(J∙mol−1∙K−1)293 K 303 K 313 K −25.34 −26.39 −27.41 4.95 103.42 Notes: ΔG—Gibbs free energy change; ΔH—Enthalpy change; ΔS—Entropy change. 表 6 Ti3CNTx/TMAOH在不同水环境下去除Sr2+前后的主要水质参数
Table 6. Main water quality parameters before and after Sr2+ removal by Ti3CNTx/TMAOH in different water environments
pH Na+/
(mg∙L−1)K+/
(mg∙L−1)Mg2+/
(mg∙L−1)Ca2+/
(mg∙L−1)Sr2+/
(mg∙L−1)TW 6.23 8.230 3.382 9.823 45.46 5.500 1.0 g∙L−1 8.129 2.999 7.777 23.38 1.572 3.0 g∙L−1 7.895 2.861 3.772 7.616 0.3411 LW 7.12 23.2 39.98 44.33 98.57 5.982 1.0 g∙L−1 228.1 38.00 41.39 80.69 3.347 3.0 g∙L−1 216.1 33.86 35.93 56.65 1.885 -
[1] LIU F F, ZHOU A G, CHEN J F, et al. Preparation of Ti3C2 and Ti2C MXenes by fluoride salts etching and methane adsorptive properties[J]. Applied Surface Science,2017,416:781-789. doi: 10.1016/j.apsusc.2017.04.239 [2] 杨挺. 核电站化学废水的处理技术浅析[J]. 科技视界, 2019(1):212-213, 216. doi: 10.19694/j.cnki.issn2095-2457.2019.01.092YANG Ting. Treatment technology of chemical wastewater in nuclear power station[J]. Scientific and Technological Horizon,2019(1):212-213, 216(in Chinese). doi: 10.19694/j.cnki.issn2095-2457.2019.01.092 [3] WANG Y, NIU B, ZHANG X, et al. Review—Ti3C2Tx MXene: An emerging two-dimensional layered material in water treatment[J]. ECS Journal of Solid State Science and Technology,2021,10(4):047002. doi: 10.1149/2162-8777/abf2de [4] HE X, JIN S, MIAO L, et al. A 3D hydroxylated MXene/carbon nanotubes composite as scaffold for dendrite-free sodium-metal electrodes[J]. Angewandte Chemie,2020,59(38):16705-16711. doi: 10.1002/anie.202006783 [5] YAGHOUB M. MXenes and other 2D nanosheets for modification of polyamide thin film nanocomposite membranes for desalination[J]. Separation and Purification Technology,2022,289:120777. doi: 10.1016/j.seppur.2022.120777 [6] HWANG S K, KANG S M, RETHINASABAPATHY M, et al. MXene: An emerging two-dimensional layered material for removal of radioactive pollutants[J]. Chemical Engineering Journal,2020,397:125428. doi: 10.1016/j.cej.2020.125428 [7] LU M, HAN W, LI H, et al. There is plenty of space in the MXene layers: The confinement and fillings[J]. Journal of Energy Chemistry,2020,48:344-363. doi: 10.1016/j.jechem.2020.02.032 [8] IBRAHIM Y, KASSAB A, EID K, et al. Unveiling fabrication and environmental remediation of MXene-based nanoarchitectures in toxic metals removal from wastewater: Strategy and mechanism[J]. Nanomaterials,2020,10(5):885-914. doi: 10.3390/nano10050885 [9] LI S, WANG L, PENG J, et al. Efficient thorium(IV) removal by two-dimensional Ti2CTx MXene from aqueous solution[J]. Chemical Engineering Journal,2019,366:192-199. doi: 10.1016/j.cej.2019.02.056 [10] RETHINASABAPATHY M, HWANG K S, KANG S M, et al. Amino-functionalized POSS nanocage-intercalated titanium carbide (Ti3C2Tx) MXene stacks for efficient cesium and strontium radionuclide sequestration[J]. Journal of Hazardous Materials,2021,418:126315. doi: 10.1016/j.jhazmat.2021.126315 [11] WANG L, TAO W, YUAN L, et al. Rational control of the interlayer space inside two-dimensional titanium carbides for highly efficient uranium removal and imprisonment[J]. Chemical Communications,2017,53(89):12084-12087. doi: 10.1039/C7CC06740B [12] ZHANG Z G, GU P, ZHANG M D, et al. Synthesis of a robust layered metal sulfide for rapid and effective removal of Sr2+ from aqueous solutions[J]. Chemical Engineering Journal,2019,372:1205-1215. doi: 10.1016/j.cej.2019.04.193 [13] QADA E, ALLEN S J, WALKER G M. Adsorption of basic dyes from aqueous solution onto activated carbons[J]. Chemical Engineering Journal,2008,135(3):174-184. doi: 10.1016/j.cej.2007.02.023 [14] YU B, YUEN A, XU X, et al. Engineering MXene surface with POSS for reducing fire hazards of polystyrene with enhanced thermal stability[J]. Journal of Hazardous Materials,2021,401:123342. doi: 10.1016/j.jhazmat.2020.123342 [15] DENG S B, BAI R B. Aminated polyacrylonitrile fibers for humic acid adsorption: Behaviors and mechanisms[J]. Environmental Science & Technology,2003,37(24):5799-5805. [16] 吴刚. 材料结构表征及应用[M]. 北京: 化学工业出版社, 2001: 15-21.WU Gang. Characterization and application of material structure[M]. Beijing: Chemical Industry Press, 2001: 15-21(in Chinese). [17] LIN H, CHEN L, LU X, et al. Two-dimensional titanium carbide MXenes as efficient non-noble metal electrocatalysts for oxygen reduction reaction[J]. Science China Materials,2019,62(5):662-670. doi: 10.1007/s40843-018-9378-3 [18] XU G, WANG X, GONG S, et al. Solvent-regulated preparation of well-intercalated Ti3C2Tx MXene nanosheets and application for highly effective electromagnetic wave absorption[J]. Nanotechnology,2018,29(35):355201. doi: 10.1088/1361-6528/aac8f6 [19] QIAN A, HYEON S E, SEO J Y, et al. Capacitance changes associated with cation-transport in free-standing flexible Ti3C2Tx (T—O, F, OH) MXene film electrodes[J]. Electrochimica Acta,2018,266:86-93. doi: 10.1016/j.electacta.2018.02.019 [20] DU F, TANG H, PAN L M, et al. Environmental friendly scalable production of colloidal 2D titanium carbonitride MXene with minimized nanosheets restacking for excellent cycle life lithium-ion batteries[J]. Electrochimica Acta,2017,235:690-699. doi: 10.1016/j.electacta.2017.03.153 [21] ZHANG M D, GU P, YAN S, et al. Na/Zn/Sn/S (NaZTS): Quaternary metal sulfide nanosheets for efficient adsorption of radioactive strontium ions[J]. Chemical Engineering Journal,2020,379:122227. doi: 10.1016/j.cej.2019.122227 [22] SHAHZAD A, OH J M, RASOOL K, et al. Strontium ions capturing in aqueous media using exfoliated titanium aluminum carbide (Ti2AlC MAX phase)[J]. Journal of Nuclear Materials,2021,549:152916. doi: 10.1016/j.jnucmat.2021.152916 [23] MU W J, DU S Z, YU Q H, et al. Improving barium ion adsorption on two-dimensional titanium carbide by surface modification[J]. Dalton Transactions,2018,47(25):8375-8381. doi: 10.1039/C8DT00917A [24] SHAHZAD A, NAWAZ M, MOZTAHIDA M, et al. Ti3C2Tx MXene core-shell spheres for ultrahigh removal of mercuric ions[J]. Chemical Engineering Journal,2019,368:400-408. doi: 10.1016/j.cej.2019.02.160 [25] ZHANG L, WEI J Y, ZHAO X, et al. Removal of strontium(II) and cobalt(II) from acidic solution by manganese antimonate[J]. Chemical Engineering Journal,2016,302:733-743. doi: 10.1016/j.cej.2016.05.040 [26] WHITE D A, LABAYRU R. Synthesis of a manganese dioxide-silica hydrous composite and its properties as a sorption material for strontium[J]. Industrial and Engineering Chemistry Research,1991,30(1):207-210. doi: 10.1021/ie00049a031 [27] WEN T, WU X L, LIU M C, et al. Efficient capture of strontium from aqueous solutions using graphene oxide-hydroxyapatite nanocomposites[J]. Dalton Transactions,2014,43(20):7464-7472. doi: 10.1039/c3dt53591f [28] DING N, KANATZIDIS M G. Selective incarceration of caesium ions by Venus flytrap action of a flexible framework sulfide[J]. Nature Chemistry,2010,2(3):187-191. doi: 10.1038/nchem.519 [29] MENG R, CHEN T, ZHANG Y, et al. Development, modification, and application of low-cost and available biochar derived from corn straw for the removal of vanadium (V) from aqueous solution and real contaminated groundwater[J]. RSC Advances,2018,8(38):21480-21494. doi: 10.1039/C8RA02172D [30] DENG S B, YU G, XIE S H, et al. Enhanced adsorption of arsenate on the aminated fibers: Sorption behavior and uptake mechanism[J]. Langmuir,2008,24(19):10961-10967. doi: 10.1021/la8023138 [31] FARD A K, MCKAY G, CHAMOUN R, et al. Barium removal from synthetic natural and produced water using MXene as two dimensional (2-D) nanosheet adsorbent[J]. Chemical Engineering Journal,2017,317:331-342. doi: 10.1016/j.cej.2017.02.090 [32] XU F J, WANG Z H, YANG W T. Surface functionalization of polycaprolactone films via surface-initiated atom transfer radical polymerization for covalently coupling cell-adhesive biomolecules[J]. Biomaterials,2010,31(12):3139-3147. doi: 10.1016/j.biomaterials.2010.01.032 [33] DENG S, ZHENG Y Q, XU F J, et al. Highly efficient sorption of perfluorooctane sulfonate and perfluorooctanoate on a quaternized cotton prepared by atom transfer radical polymerization[J]. Chemical Engineering Journal,2012,193-194:154-160. doi: 10.1016/j.cej.2012.04.005 [34] ZHANG G, WANG T, XU Z, et al. Synthesis of amino-functionalized Ti3C2Tx MXene by alkalization-grafting modification for efficient lead adsorption[J]. Chemical Communications,2020,56(76):11283-11286. doi: 10.1039/D0CC04265J [35] CHENG Z, ZHU X, SHI Z L, et al. Polymer microspheres with permanent antibacterial surface from surface-initiated atom transfer radical polymerization[J]. Industrial & Engineering Chemistry Research,2005,44(18):7098-7104. [36] ZHANG P, WANG L, HUANG Z, et al. Aryl diazonium-assisted amidoximation of MXene for boosting water stability and uranyl sequestration via electrochemical sorption[J]. ACS Applied Materials & Interfaces,2020,12(13):15579-15587. [37] CHEN S, XIANG Y, BANKS M K, et al. Polyoxometalate-coupled MXene nanohybrid via poly(ionic liquid) linkers and its electrode for enhanced supercapacitive performance[J]. Nanoscale,2018,10(42):20043-20052. doi: 10.1039/C8NR05760E [38] KIM S J, KOH H J, REN C E, et al. Metallic Ti3C2Tx MXene gas sensors with ultrahigh signal-to-noise ratio[J]. ACS Nano,2018,12(2):986-993. doi: 10.1021/acsnano.7b07460 [39] WANG H, CUI H, SONG X, et al. Facile synthesis of heterojunction of MXenes/TiO2 nanoparticles towards enhanced hexavalent chromium removal[J]. Journal of Colloid and Interface Science,2020,561:46-57. doi: 10.1016/j.jcis.2019.11.120