SYNTHESIS OF CORE-SHELL CHITOSAN-Ag/TiO2 COMPOSITE BEADS FOR DEGRADATION OF IBUPROFEN
-
摘要: 针对目前污水中布洛芬等典型PPCPs类污染物光催化降解效率低、催化剂回收难度大等难题,以壳聚糖为载体,通过负载银掺杂TiO2,制备有机核-无机壳结构的CTS-Ag/TiO2复合小球,开展了光催化降解布洛芬性能研究。结果表明:壳聚糖紧密团聚成核,银掺杂TiO2分布在壳聚糖表面,共同形成了有机核-无机壳结构。在紫外光作用下,复合小球对布洛芬展现出良好的去除效能,在最佳条件下(CAT投加量为4 g/L,布洛芬初始浓度为1 mg/L,pH值为6),处理60 min后布洛芬去除率达到96.1%,经过5次回收利用,去除率仍可达到85.0%。新型有机核-无机壳复合结构以及壳聚糖中含碳基团和含氮物质在价带上形成的附加带,使CAT复合小球在强化吸附、光催化和稳定性的同时,提高了材料可重复使用性。Ag在TiO2表面掺杂形成的无机壳包裹在壳聚糖形成的有机核表面,使光生电子更易从TiO2转移到Ag上并积累,减少电子-空穴对的复合,提高了CAT的光催化效率。活性组分淬灭实验表明,·O2-和空穴氧化是引起布洛芬降解的主要活性成分。Abstract: For the current obstacles of low photocatalytic degradation efficiency of typical PPCPs such as ibuprofen and the limited reusability restricts,the organic core-inorganic shell structured chitosan-Ag/TiO2(CAT) composite beads were successfully synthesized using chitosan as the carrier and silver-doped TiO2 as the photocatalyst,and used for the degradation of ibuprofen.The results illustrated that chitosan agglomerated tightly to form a core,and the silver-doped TiO2 was distributed on the surface of the chitosan,eventually forming an organic core-inorganic shell structure.The composite beads showed a good removal efficiency on ibuprofen under UV irradiation.The ibuprofen removal efficiency of 96.1% was achievable in 60 min under optimal operational condition (catalyst load=4 mg/L,initial IBP concentration=1 mg/L,initial pH=6).The results showed that even after the fifth photocatalytic cycle,the removal efficiency after 60 min was still as high as 85.0%.Novel core (organic)-shell (inorganic) composite structure and the additional band above the valence band was created by the carbon-contain groups and the doped N species of chitosan,which could enhance the absorption,photocatalysis,stability and reusability of the CAT composite beads.The inorganic shell formed by doping Ag on the surface of TiO2 was wrapped on the surface of the organic core formed by chitosan.So photogenerated electrons transfer readily from TiO2 to Ag with heavy accumulation due to doping Ag on TiO2 surfaces,which may reduce the recombination of electron-hole pairs and thus enhance the photocatalytic efficiency.The reactive species scavenging experiments showed that·O2- mediated reactions and direct-hole oxidation were the major degradation reactions.
-
Key words:
- chitosan /
- Ag/TiO2 composite bead /
- ibuprofen /
- core-shell structure /
- photocatalytic degradation /
- nitrogen doped
-
[1] MÉNDEZ-ARRIAGA F, ESPLUGAS S, GIMÉNEZ J. Photocatalytic degradation of non-steroidal anti-inflammatory drugs with TiO2 and simulated solar irradiation[J]. Water Research, 2008, 42(3):585-594. [2] HUANG Q X, YU Y Y, TANG C M, et al. Occurrence and behavior of non-steroidal anti-inflammatory drugs and lipid regulators in wastewater and urban river water of the Pearl River Delta, South China[J]. Journal of Environmental Monitoring, 2011, 13(4):855-863. [3] GEORGAKI I, VASILAKI E, KATSARAKIS N. A study on the degradation of carbamazepine and ibuprofen by TiO2&ZnO photocatalysis upon UV/visible-light irradiation[J]. American Journal of Analytical Chemistry, 2014, 5(8):518-534. [4] MICHAEL I, RIZZO L, MCARDELL C S, et al. Urban wastewater treatment plants as hotspots for the release of antibiotics in the environment:a review[J]. Water Research, 2013, 47(3):957-995. [5] LIANG R W, LUO S G, JING F F, et al. A simple strategy for fabrication of Pd@MIL-100(Fe) nanocomposite as a visible-light-driven photocatalyst for the treatment of pharmaceuticals and personal care products (PPCPs)[J]. Applied Catalysis B:Environmental, 2015, 176/177:240-248. [6] ACHILLEOS A, HAPESHI E, XEKOUKOULOTAKIS N P, et al. UV-A and solar photodegradation of ibuprofen and carbamazepine catalyzed by TiO2[J]. Separation Science and Technology, 2010, 45(11):1564-1570. [7] FEI J B, LI J B. Controlled preparation of porous TiO2-Ag nanostructures through supramolecular assembly for plasmon-enhanced photocatalysis[J]. Advanced Matercals, 2015, 27(2):314-319. [8] KAMARI Y, GHIACI M. Preparation and characterization of ibuprofen/modified chitosan/TiO2 hybrid composite as a controlled drug-delivery system[J]. Microporous and Mesoporous Materials, 2016, 234:361-369. [9] TANG L Z, TANG F, LI M, et al. Facile synthesis of Ag@AgCl-contained cellulose hydrogels and their application[J]. Colloids and Surfaces A:Physicochemical and Engineering Aspects, 2018, 553:618-623. [10] ULLAH S, FERREIRA-NETO E P, PASA A A, et al. Enhanced photocatalytic properties of core@shell SiO2@TiO2 nanoparticles[J]. Applied Catalysis B:Environmental, 2015, 179:333-343. [11] POUGIN A, DODEKATOS G, DILLA M, et al. Au@TiO2 core-shell composites for the photocatalytic reduction of CO2[J]. Chemistry-A European Journal, 2018, 24(47):12416-12425. [12] WANG K, XING Z P, MENG D, et al. Hollow MoSe2@Bi2S3/CdS core-shell nanostructure as dual z-scheme heterojunctions with enhanced full spectrum photocatalytic-photothermal performance[J]. Applied Catalysis B:Environmental, 2021, 281:119482. [13] REDDY K R, HASSAN M, GOMES V G. Hybrid nanostructures based on titanium dioxide for enhanced photocatalysis[J]. Applied Catalysis A:General, 2015, 489:1-16. [14] CHEN L N, FENG Q, YANG W, et al. Photocatalytic process optimization by numerical simulation based on the removal efficiency of carbamazepine under different operating conditions[J]. Polish Journal of Environmental Studies, 2021, 30(3):2013-2025. [15] XIA D H, LO I M C. Synthesis of magnetically separable Bi2O4/Fe3O4 hybrid nanocomposites with enhanced photocatalytic removal of ibuprofen under visible light irradiation[J]. Water Research, 2016, 100:393-404. [16] YI J H, HUANG L L, WANG H J, et al. AgI/TiO2 nanobelts monolithic catalyst with enhanced visible light photocatalytic activity[J]. Journal of Hazardous Materials, 2015, 284:207-214. [17] BADER H, STURZENEGGER V, HOIGNÉ J. Photometric method for the determination of low concentrations of hydrogen peroxide by the peroxidase catalyzed oxidation of N,N-diethyl-p-phenylenediamine (DPD)[J]. Water Research, 1988, 22(9):1109-1115. [18] HALDORAI Y, SHIM J J. Novel chitosan-TiO2 nanohybrid:preparation, characterization, antibacterial, and photocatalytic properties[J]. Polymer Composites, 2014, 35(2):327-333. [19] SHAO Y, CAO C S, CHEN S L, et al. Investigation of nitrogen doped and carbon species decorated TiO2 with enhanced visible light photocatalytic activity by using chitosan[J]. Applied Catalysis B:Environmental, 2015, 179:344-351. [20] LEONG K H, LIU S L, SIM L C, et al. Surface reconstruction of titania with g-C3N4 and Ag for promoting efficient electrons migration and enhanced visible light photocatalysis[J]. Applied Surface Science, 2015, 358:370-376. [21] de GODOI F C, RODRIGUEZ-CASTELLON E, GUIBAL E, et al. An XPS study of chromate and vanadate sorption mechanism by chitosan membrane containing copper nanoparticles[J]. Chemical Engineering Journal, 2013, 234:423-429. [22] WANG X P, LIM T T. Highly efficient and stable Ag-AgBr/TiO2 composites for destruction of Escherichia coli under visible light irradiation[J]. Water Research, 2013, 47(12):4148-4158. [23] ZHUO N, LAN Y Q, YANG W B, et al. Adsorption of three selected pharmaceuticals and personal care products (PPCPs) onto MIL-101(Cr)/natural polymer composite beads[J]. Separation and Purification Technology, 2017, 177:272-280. [24] KUMAR R, RASHID J, BARAKAT M A. Zero valent Ag deposited TiO2 for the efficient photocatalysis of methylene blue under UV-C light irradiation[J]. Colloids and Interface Science Communications, 2015, 5:1-4. [25] XIAO G, SU H J, TAN T W. Synthesis of core-shell bioaffinity chitosan-TiO2 composite and its environmental applications[J]. Journal of Hazardous Materials, 2015, 283:888-896. [26] BILGIN SIMSEK E, KILIC B, ASGIN M, et al. Graphene oxide based heterojunction TiO2-ZnO catalysts with outstanding photocatalytic performance for bisphenol:a, ibuprofen and flurbiprofen[J]. Journal of Industrial and Engineering Chemistry, 2018, 59:115-126. [27] JACOBS L E, FIMMEN R L, CHIN Y P, et al. Fulvic acid mediated photolysis of ibuprofen in water[J]. Water Research, 2011, 45(15):4449-4458. [28] RODRÍGUEZ E M, MÁRQUEZ G, TENA M, et al. Determination of main species involved in the first steps of TiO2 photocatalytic degradation of organics with the use of scavengers:the case of ofloxacin[J]. Applied Catalysis B:Environmental, 2015, 178:44-53. [29] KHAN M, FUNG C S L, KUMAR A, et al. Magnetically separable BiOBr/Fe3O4@SiO2 for visible-light-driven photocatalytic degradation of ibuprofen:mechanistic investigation and prototype development[J]. Journal of Hazardous Materials, 2019, 365:733-743.
点击查看大图
计量
- 文章访问数: 280
- HTML全文浏览量: 25
- PDF下载量: 20
- 被引次数: 0