MoO3/TiO2纳米管的制备及其光催化降解多环芳烃的机制
Preparation of MoO3/TiO2 nanotubes and the mechanism study for the photocatalytic degradation of PAHs
-
摘要: 本研究将热分解法制备的MoO3与水热法制备的TiO2纳米管复合,得到具有高太阳光催化活性的MoO3/TiO2纳米管异质结催化剂.研究中以芘为模型多环芳烃(polycyclic aromatic hydrocarbons,PAHs),探究了MoO3/TiO2纳米管模拟在太阳光下催化降解PAHs的效果及效率提升的机制.结果表明,MoO3和TiO2纳米管间形成的p-n异质结结构,降低了材料的能带间隙而获得更高的可见光利用效率,并有效促进了电子和空穴的分离,从而提高了复合材料的光催化活性.1% MoO3/TiO2纳米管催化降解芘速率(k)较MoO3和TiO2(锐钛矿)分别提升了5.3倍和1.5倍.催化体系中产生的·OH和光生空穴在芘的降解中起主要作用.
-
关键词:
- MoO3 /
- TiO2 /
- MoO3/TiO2纳米管 /
- 芘 /
- 光催化
Abstract: In this study, a highly solar active MoO3/TiO2 nanotubes catalyst was prepared by calcining the solid-state decomposition derived MoO3 and hydrothermal synthesized TiO2 nanotubes. Using pyrene as a model PAH, the photocatalytic activity of MoO3/TiO2 nanotubes was evaluated under solar light irradiation, and the mechanism of improved photocatalytic activity was investigated by experiments and material characterizations. The results showed that the p-n heterojunction formed between MoO3 and TiO2, which reduced the band gap energy of TiO2, and the photocatalytic activity of the composite was improved via obtaining higher visible light utilization efficiency and promoting electron-hole pairs separation. The degradation rate (k) of pyrene by 1%MoO3/TiO2 nanotubes was 5.3 times and 1.5 times of MoO3 and TiO2 (anatase), respectively. Moreover, the·OH and holes were found to play major roles in the photodegradation of pyrene.-
Key words:
- MoO3 /
- TiO2 /
- MoO3/TiO2 nanotubes /
- pyrene /
- photocatalytic
-
[1] Toxic and priority pollutants under the clean water act:Priority pollutant List[S]. US EPA, 2014. [2] SCHNEIDER J, GROSSER R, JAYASIMHULU K, et al. Degradation of pyrene, benz[a]anthracene, and benzo[a]pyrene by Mycobacterium sp strain rjgii-135, isolated from a former coal gasification site[J]. Applied and Environmental Microbiology, 1996, 62(1):13-19. [3] WARD C P, SHARPLESS C M, VALENTINE D L, et al. Partial photochemical oxidation was a dominant fate of Deepwater Horizon surface oil[J]. Environmental Science & Technology, 2018, 52(4):1797-1805. [4] FUJISHIMA A, HONDA K. Electrochemical photolysis of water at a semiconductor electrode[J]. Nature, 1972, 238(5358):37-38. [5] BHATTACHARYYA K, MAJEED J, DEY K K, et al. Effect of Mo-incorporation in the TiO2 lattice:A mechanistic basis for photocatalytic dye degradation[J]. The Journal of Physical Chemistry C, 2014, 118(29):15946-15962. [6] JIN Y J, DAI Z Y, LIU F, et al. Bactericidal mechanisms of Ag2O/TNBs under both dark and light conditions[J]. Water Research, 2013, 47(5):1837-1847. [7] CHENG K Y, CAI Z Q, FU J, et al. Synergistic adsorption of Cu(Ⅱ) and photocatalytic degradation of phenanthrene by a jaboticaba-like TiO2/titanate nanotube composite:An experimental and theoretical study[J]. Chemical Engineering Journal, 2019, 358:1155-1165. [8] YANG Y, LI X J, CHEN J T, et al. Effect of doping mode on the photocatalytic activities of Mo/TiO2[J]. Journal of Photochemistry and Photobiology A:Chemistry, 2004, 163(3):517-522. [9] CAI Z Q, ZHAO X, WANG T, et al. Reusable platinum-deposited anatase/hexa-titanate nanotubes:Roles of reduced and oxidized platinum on enhanced solar-light-driven photocatalytic activity[J]. ACS Sustainable Chemistry & Engineering, 2017, 5(1):547-555. [10] LIU W, BORTHWICK A G L, LI X, et al. High photocatalytic and adsorptive performance of anatase-covered titanate nanotubes prepared by wet chemical reaction[J]. Microporous and Mesoporous Materials, 2014, 186:168-175. [11] XIE Z J, FENG Y P, WANG F L, et al. Construction of carbon dots modified MoO3/g-C3N4, Z-scheme photocatalyst with enhanced visible-light photocatalytic activity for the degradation of tetracycline[J]. Applied Catalysis B:Environmental, 2018, 229:96-104. [12] GAO Y, ELDER S A. TEM study of TiO2 nanocrystals with different particle size and shape[J]. Materials Letters, 2000, 44(3-4):228-232. [13] 韩维屏, 尹喜林, 李永战. MoO3与TiO2界面化学分散的研究[J]. 催化学报, 1992, 13(1):19-24. HAN W P, YIN X L, LI Y Z. Study on chemical dispersion of MoO3 and TiO2 interface[J]. Chinese Journal of Catalysis, 1992, 13(1):19-24(in Chinese).
[14] LU M X, SHAO C L, WANG K X, et al. p-MoO3 nanostructures/n-TiO2 nanofiber heterojunctions:Controlled fabrication and enhanced photocatalytic properties[J]. ACS Applied Materials and Interfaces, 2014, 6(12):9004-9012. [15] SVIRIDOVA T V, SADOVSKAУA L YU, SHCHUKINA E M, et al. Nanoengineered thin-film TiO2/h-MoO3 photocatalysts capable to accumulate photoinduced charge[J]. Journal of Photochemistry and Photobiology A:Chemistry, 2016, 327:44-50. [16] KIM S, KIM M, HWANG S H, et al. Enhancement of photocatalytic activity of titania-titanate nanotubes by surface modification[J]. Applied Catalysis B:Environmental, 2012, 123-124:391-397. [17] LIU H, LV T, ZHU C K, et al. Direct bandgap narrowing of TiO2/MoO3 heterostructure composites for enhanced solar-driven photocatalytic activity[J]. Solar Energy Materials and Solar Cells, 2016, 153:1-8. [18] CHEN Y J, XIAO G, WANG T S, et al. α-MoO3/TiO2 core/shell nanorods:Controlled-synthesis and low-temperature gas sensing properties[J]. Sensors and Actuators B Chemical, 2011, 155(1):270-277. [19] NAVGIRE M, YELWANDE A, TAYDE D, et al. Photodegradation of molasses by a MoO3-TiO2 nanocrystalline composite material[J]. Chinese Journal of Catalysis, 2012, 33(2-3):261-266. [20] HU R R, ZHONG S H. Surface structure and photon absorption property of supported coupled semiconductors MoO3-TiO2/SiO2[J]. Chinese Journal of Chemical Physics, 2005, 18(3):389-394. [21] LI N, LI Y M, ZHOU Y J, et al. Interfacial-charge-transfer-induced photochromism of MoO3@TiO2 crystalline-core amorphous-shell nanorods[J]. Solar Energy Materials and Solar Cells, 2017, 160:116-125. [22] ZHANG J, XI J H, JI Z G. Mo plus N codoped TiO2 sheets with dominant (001) facets for enhancing visible-light photocatalytic activity[J]. Journal of Materials Chemistry, 2012, 22(34):17700-17708.
计量
- 文章访问数: 2210
- HTML全文浏览数: 2210
- PDF下载数: 52
- 施引文献: 0