多孔TiO2空心球降解挥发性有机物的性能
The degradation of volatile organic compounds by porous TiO2 hollow spheres
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摘要: 为实现挥发性有机物(volatile organic compounds,VOCs)的高效吸附-矿化,本研究以SiO2为模板、十二胺为成孔剂制备了不同壁厚的多孔TiO2空心球,并以相同壁厚的SiO2@TiO2实心核壳材料做对比研究空心结构的光学和反应特性.采用透射电镜、氮气等温吸附-脱附、X射线衍射、紫外-可见吸收光谱、表面光电压谱等手段表征材料物化结构,以甲苯为VOCs的代表进行光催化降解实验.结果表明,多孔空心TiO2的比表面积和吸附性能均优于实心TiO2.同时,空心腔体显著提高了光吸收率和载流子分离效率.当壁厚为27 nm时空心材料对甲苯的降解速率和矿化效率分别达到了1.14 mg·m-3·min-1和81.3%,是相同壁厚条件下实心材料的2.15倍和2.31倍.Abstract: To enhance the absorption and mineralization of volatile organic compounds (VOCs), porous TiO2 hollow spheres with different shell-thickness were prepared using SiO2 as template and dodecylamine as the pore-forming agent. Porous SiO2@TiO2 core-shell solid sphere with same shell thickness were synthesized as the control materials. The structural characteristics were characterized by transmission electron microscopy, nitrogen isothermal adsorption-desorption, X-ray diffraction, ultraviolet-visible absorption spectroscopy and surface photovoltage spectroscopy. The photocatalytic degradation experiments were carried out using toluene as a model VOCs. The results showed that the specific surface area, and adsorption performance of the hollow materials were significantly higher than those of the solid materials.Moreover, the hollow structure obviously enhanced the light absorption and separation efficiency of charge carriers compared with the solid TiO2. The reaction rate and mineralization efficiency of toluene for the TiO2 hollow reached up to 1.14 mg·m-3·min-1 and 81.3%, 2.15 and 2.31 times higher than those of the solid material with same shell-thickness, respectively.
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Key words:
- Shell-thickness /
- TiO2 hollow spheres /
- Photocatalysis /
- VOCs
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[1] 付晓辛, 王新明, FRANCOIS BERNARD. 空气清新剂中挥发性有机物的组成及其对室内空气质量的潜在影响[J]. 环境化学, 2012, 31(2):243-248. FU X X, WANG X M, FRANCOIS B. Volatile organic compounds in air fresheners and their potential impacts on indoor air quality[J]. Environmental Chemistry, 2012, 31(2):243-248(in Chinese).
[2] 王铁宇, 李奇锋, 吕永龙. 我国VOCs的排放特征及控制对策研究[J]. 环境科学, 2013, 12(12):4756-4763. WANG T Y, LI Q F, LYU Y L. Study on emission characteristics and control strategies of VOCs in China[J]. Environmental Science, 2013, 12(12):4756-4763(in Chinese).
[3] LU H, ZHU L. Pollution patterns of polycyclic aromatic hydrocarbons in tobacco smoke[J]. Journal of Hazardous Materials, 2007, 139(2):193-198. [4] WANG S B, ANG H M, TADE M O. Volatile organic compounds in indoor environment and photocatalytic oxidation:State of the art[J]. Environment International, 2007, 33(5):694-705. [5] LU H, ZHU L Z, CHEN S. Pollution level, phase distribution and health risk of polycyclic aromatic hydrocarbons in indoor air at public places of Hangzhou, China[J]. Environmental Pollution, 2008, 152(3):569-575. [6] KHAN F I, Ghoshal A K. Removal of volatile organic compounds from polluted air[J]. Journal of Loss Prevention in the Process Industries, 2000, 13(6):527-545. [7] TAN J, WANG P, YAN S. A review and recent developments in photocatalytic water-splitting using TiO2 for hydrogen productions[J]. Renewable & Sustainable Energy Reviews, 2007, 11(3):401-425. [8] OUYANG X H, PENG R X, AI L, et al. Efficient polymer solar cells employing a non-conjugated small-molecule electrolyte[J]. Nature Photonics, 2015, 9(8):520-524. [9] TU W, ZHOU Y, LIU Q, et al. Robust Hollow spheres consisting of alternating titania nanosheets and graphene nanosheets with high photocatalytic activity for CO2 Conversion into renewable fuels[J]. Advanced Functional Materials, 2012, 22(6):1215-1221. [10] RETI B, KISS G I, TAMAS, et al. Carbon sphere templates for TiO2 hollow structures:Preparation, characterization and photocatalytic activity[J]. Catalysis Today, 2017, 284:160-168. [11] SHANG S, JIAO X, CHEN D. Template-free fabrication of TiO2 hollow spheres and their photocatalytic properties[J]. Acs Applied Materials & Interfaces, 2012, 4(4):860-865. [12] WANG H, WU Z, LIU Y. A simple two-step template approach for preparing carbon-doped mesoporous TiO2 hollow microspheres[J]. Journal of Physical Chemistry C, 2009, 113(30):13317-13324. [13] CHEN J, NIE X, SHI H, et al. Synthesis of TiO2 hollow sphere multimer photocatalyst by etching titanium plate and its application to the photocatalytic decomposition of gaseous styrene[J]. Chemical Engineering Journal, 2013, 228(5):834-842. [14] WANG Z, ZHOU L, LOU X W. Metal oxide hollow nanostructures for lithium-ion batteries[J]. Advanced Materials, 2012, 24(14):1903-1911. [15] LYU J Z, ZHU L Z, BURDA C. Considerations to improve adsorption and photocatalysis of low concentration air pollutants on TiO2[J]. Catalysis Today, 2014, 225(1):24-33. [16] STOBER W, FINK A, BOHN E. Controlled growth of monodisperse silica spheres in the micron size range[J]. Journal of Colloid & Interface Science, 1968, 26(1):62-69. [17] LYU J Z, ZHU L, BURDA C. Optimizing nanoscale TiO2 for adsorption-enhanced photocatalytic degradation of low-concentration air pollutants[J]. Chemcatchem, 2013, 5(10):3114-3123. [18] LYU J Z, GAO J X, ZHANG M, et al. Construction of homojunction-adsorption layer on anatase TiO2 to improve photocatalytic mineralization of volatile organic compounds[J]. Applied Catalysis B-Environmental, 2017, 202:667-674. [19] LYU J Z, SUN L N, ZHONG J B, et al. Shielding of surface photogenerated charges by SiO2 coating for the photocatalytic degradation of air pollutants[J]. Chemical Engineering Journal, 2016, 303:314-321. [20] ZHOU W, SUN F, PAN K, et al. Well-ordered large-pore mesoporous anatase TiO2 with remarkably high thermal stability and improved crystallinity:preparation, characterization, and photocatalytic performance[J]. Advanced Functional Materials, 2011, 21(10):1922-1930. [21] GUAN B Y, YU L, LI, J, et al. A universal cooperative assembly-directed method for coating of mesoporous TiO2 nanoshells with enhanced lithium storage properties[J]. Science Advances, 2016, 2(3):1550-1554. [22] LIU B, ZHAO X, NAkATA, et al. Construction of hierarchical titanium dioxide nanomaterials by tuning the structure of butoxide complexes from 2 to 3 dimensional[J]. Journal of Materials Chemistry A, 2013, 1(16):4993-5000. [23] 陈礼平. 复合型TiO2纳米管阵列光生电荷行为及光催化性质研究[D]. 长春:吉林大学, 2014. CHENG L P. Photoinduced charge behavior and photocatalytic properties of composite TiO2 nanotube arrays[D]. Chang Chun:Jilin University, 2014(in Chinese). [24] YANG M Q, ZHANG Y W, PANG G S, et al. Preparation of Cu2O hollow nanospheres under reflux conditions[J]. European Journal of Inorganic Chemistry, 2007(24):3841-3844. [25] SANG B K, HONG S C. Kinetic study for photocatalytic degradation of volatile organic compounds in air using thin film TiO2 photocatalyst[J]. Applied Catalysis B-Environmental, 2002, 35(4):305-315.
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