Preparation of WO3/g-C3N4 heterojunction catalyst and its oxidative desulfurization performance
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摘要: 以尿素和钨酸铵为原料采用浸渍法制备了金属氧化物三氧化钨（WO3）与石墨相氮化碳（g-C3N4）异质结复合材料WO3/g-C3N4。采用XRD、UV-vis、SEM、PL和XPS表征手段考察了催化剂的理化性质，发现WO3与g-C3N4存在较好的相互作用和电子转移，保证了WO3/g-C3N4本身所具有较高的氧化脱硫活性。以WO3/g-C3N4作为催化剂，过氧化氢异丙苯为氧化剂，考察其光催化氧化脱硫性能，在反应温度80℃，O/S物质的量比为3.0的反应条件下，反应180 min，二苯并噻吩（DBT）转化率可以达到72.79%。通过游离基捕获实验，发现超氧自由基（·O2-）、电子（e-）、羟基自由基（·OH）起到了促进反应速率的作用，并对该体系的反应机理进行了探讨。Abstract: Graphite phase carbon nitride (g-C3N4) and metal oxide tungsten trioxide (WO3) heterojunction nanocomposites WO3/g-C3N4 were prepared by roasting from urea and ammonium tungstate. The physical and chemical properties of the catalysts were investigated by means of XRD, UV-vis, SEM, PL and XPS. The characterization indicated that WO3 and g-C3N4 interacted well in the catalysts, and electron transfer occurred between them, which ensured high oxidative desulfurization activity of WO3/g-C3N4. Supported catalyst WO3/g-C3N4 was prepared using WO3 as the support. Isopropyl peroxide was used as the oxidant to investigate the catalyst performance in oxidative desulfurization of the simulated oil. Under the reaction conditions of 80℃ and the content ratio of O/S at 3, a 72.79% of dibenzothiophene (DBT) conversion could be achieved after 180 min. It was fund that the superoxide free radicals (·O2-), electron (e-) and hydroxyl free radicals (·OH) promoted the reaction rate through free radical capture experiment and the reaction mechanism was proposed.
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Key words:
- WO3 /
- g-C3N4 /
- heterojunction /
- oxidative desulfurization /
- electron transfer
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图 1 g-C3N4、WO3、WO3(20%-80%)/g-C3N4样品的XRD谱图
Figure 1 XRD spectra of g-C3N4, WO3, WO3 (20%-80%)/g-C3N4
图 2 g-C3N4(a)、WO3(20%)/g-C3N4(b)样品的SEM照片
Figure 2 SEM images of g-C3N4 (a), WO3 (20%)/g-C3N4 (b) samples
图 4 WO3、g-C3N4、WO3(20%)/g-C3N4的XPS谱图
(a): survey spectra of WO3 and WO3(20%)/g-C3N4; g-C3N4 and WO3(20%)/g-C3N4: (b): C 1s; (c): N 1s; (d): O 1s; (e): W 4f; pure WO3: (f): W 4f
Figure 4 XPS spectra of WO3, g-C3N4, WO3(20%)/g-C3N4
图 5 g-C3N4、WO3、WO3(20%)/g-C3N4样品的UV-vis谱图
Figure 5 UV-vis spectra of g-C3N4, WO3, WO3(20%)/g-C3N4
图 6 WO3、g-C3N4、WO3(20%)/g-C3N4样品的PL谱图
Figure 6 PL spectra of WO3, g-C3N4, WO3(20%)/g-C3N4
图 7 不同制备方法制备出来的催化剂的氧化脱硫效果
reaction conditions: 80 ℃, O/S(mol ratio)=3.0, 180 min, the amount of catalyst was 0.1 g
Figure 7 Oxidative desulfurization performance of the catalysts prepated by different methods
图 8 不同负载量催化剂对DBT转化率的影响
Figure 8 DBT conversion of the catalysts with different loadings
图 9 不同温度下催化剂对DBT转化率的影响
reaction conditions: O/S(mol ratio)=3.0, 180 min, the amount of WO3(20%)/g-C3N4 was 0.1 g
Figure 9 DBT conversion of the catalyst at different temperatures
图 10 氧硫物质的量比对DBT在反应体系中的影响
reaction conditions: 80 ℃, 180 min, the amount of WO3(20%)/g-C3N4 was 0.1 g
Figure 10 Influence of oxygen-sulfur molar ratio on DBT conversion
图 11 WO3(20%)/g-C3N4催化剂的循环使用性能
reaction conditions: 80 ℃, O/S(mol ratio)=3.0, 180 min, the amount of WO3(20%)/g-C3N4 was 0.1 g
Figure 11 Catalytic performance of the fresh and the reused WO3(20%)/g-C3N4
图 12 不同捕获剂的加入对实验的影响
reaction conditions: 80 ℃, O/S(mol ratio)=3.0, 180 min, the amount of WO3(20%)/g-C3N4 was 0.05 g
Figure 12 Influence of different capture agents on the experiment
图 13 WO3/g-C3N4半导体异质结光生电子空穴迁移示意图
Figure 13 Schematic diagram of photogenic electron hole migration in WO3/g-C3N4 semiconductor heterojunction
图 14 WO3/g-C3N4氧化脱硫机理示意图
Figure 14 Oxidative desulfurization mechanism over WO3/g-C3N4 catalyst
表 1 不同催化剂的比表面积及其氧化DBT的活性
Table 1 Specific surface area and DBT oxidation activity of different catalysts
Catalyst Specific surface area A/(m2·g-1) DBT conversion x/% WO3 16.40 0 g-C3N4 57.17 1.18 WO3(20%)/g-C3N4 50.23 72.79 WO3(40%)/g-C3N4 41.35 65.4 WO3(60%)/g-C3N4 34.56 16.5 WO3(80%)/g-C3N4 27.62 9.86 reaction conditions: 80 ℃, O/S =3.0, 180 min, the amount of catalyst was 0.1 g 
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[1] 蒋克望.石墨相氮化碳(g-C3N4)的复合改性及其光催化性能研究[D].南京: 南京理工大学, 2016. http://www.doc88.com/p-0641391889595.htmlJIANG Ke-wang. Composite modification and photocatalytic properties of graphite phase carbon nitride (g-C3N4)[D]. Nanjing: Nanjing University of Science and Technology, 2016. http://www.doc88.com/p-0641391889595.html [2] 王鑫博, 李秀萍, 赵荣祥. EMIES/p-TsOH型低共熔溶剂的合成及其氧化脱硫性能的研究[J].燃料化学学报, 2019, 47(1):104-112. doi: 10.3969/j.issn.0253-2409.2019.01.014WANG Xin-bo, LI Xiu-ping, ZHAO Rong-xiang. Synthesis of EMIES/p-TsOH low eutectic solvent and its oxidative desulfurization performance[J]. J Fuel Chem Technol, 2019, 47(1):104-112. doi: 10.3969/j.issn.0253-2409.2019.01.014 [3] 李秀萍, 赵荣祥, 邢鹏飞. NiWO4/g-C3N4的制备及其在离子液体中氧化脱硫性能的研究[J].燃料化学学报, 2017, 45(11):1340-1348. doi: 10.3969/j.issn.0253-2409.2017.11.009LI Xiu-ping, ZHAO Rong-xiang, XING Peng-fei. Preparation of NiWO4/g-C3N4 and its oxidative desulfurization performance in ionic liquid[J]. J Fuel Chem Technol, 2017, 45(11):1340-1348. doi: 10.3969/j.issn.0253-2409.2017.11.009 [4] CHAN K, JUNG J L, JUN S B, KYUNGIL C, SANG H M. Hydrodesulfurization of DBT, 4-MDBT, and 4, 6-DMDBT on fluorinated CoMoS/Al2O3 catalysts[J]. Appl Catal A:Gen, 2000, 200(1/2):233-242. [5] 刘优昌, 王亮. g-C3N4/BiOBr异质结光催化剂的制备与可见光催化活性[J].燃料化学学报, 2018, 46(9):1146-1152. doi: 10.3969/j.issn.0253-2409.2018.09.014LIU You-chang, WANG Liang. Preparation and visible light catalytic activity of g-C3N4/BiOBr heterojunction photocatalyst[J]. J Fuel Chem Technol, 2018, 46(9):1146-1152. doi: 10.3969/j.issn.0253-2409.2018.09.014 [6] WANG X C, MAEDA K, THOMAS A, TAKANABE K, XIN G, CARLSSON J M, DOMEN K, ANTONIETTI M. A metal-free polymeric photocatalyst for hydrogen production from water under visible light[J]. Nat Mater, 2009, 8(1):76-80. [7] KROKE E, SCHWARZ M, HORATH-BORDON E, KROLL P, NOLL B, NORMAN A D. Tri-s-triazine derivatives. Part Ⅰ. From trichloro-tri-triazine to graphitic C3N4 structures[J]. New J Chem, 2002, 26(5):508-512. doi: 10.1039/b111062b [8] 李秀萍, 赵荣祥, 苏建勋, 艾东.磷钨酸功能化氮化碳的制备及其氧化脱硫研究[J].燃料化学学报, 2015, 43(7):870-875. doi: 10.3969/j.issn.0253-2409.2015.07.013LI Xiu-ping, ZHAO Rong-xiang, SU Jian-xun, AI Dong. Preparation of functional nitride of phosphotungstic acid and its oxidative desulfurization[J]. J Fuel Chem Technol, 2015, 43(7):870-875. doi: 10.3969/j.issn.0253-2409.2015.07.013 [9] 闫俊萍, 张中太, 唐子龙, 罗绍华.半导体基纳米复合材料光催化研究进展[J].无机材料学报, 2003, 18(5):980-988. doi: 10.3321/j.issn:1000-324X.2003.05.003YAN Jun-ping, ZHANG Zhong-tai, TANG Zi-long, LUO Shao-hua. Progress in photocatalysis of semiconductor nanocomposites[J]. J Inorg Mater, 2003, 18(5):980-988. doi: 10.3321/j.issn:1000-324X.2003.05.003 [10] TONG H X, CHEN Q Y, YIN Z L, HU H P, WU D X, YANG Y H. Preparation characterization and photo-catalytic behavior of WO3-TiO2 catalysts with oxygen vacancies[J]. Trans Nonferrous Met Soc China, 2009, 19(6):1483-1488. doi: 10.1016/S1003-6326(09)60056-X [11] SUN J X, YUAN Y P, QIU L G, JIANG X, XIE A J, SHEN Y H, ZHU J F. Fabrication of composite photocatalyst g-C3N4-ZnO and enhancement of photocatalytic activity under visible light[J]. Dalton Trans, 2012, 41(22):6756-6763. doi: 10.1039/c2dt12474b [12] YAN H J, YANG H X. TiO2-g-C3N4 composite materials for photocatalytic H2 evolution under visible light irradiation[J]. J Alloys Compd, 2011, 509:L26-L29. doi: 10.1016/j.jallcom.2010.09.201 [13] 邢鹏飞, 李秀萍, 贾宝军, 赵荣祥. MoO3/g-C3N4催化剂的制备及其氧化脱除模拟油中的硫化物[J].化工进展, 2016, 35(12):3934-3941. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=hgjz201612029XING Peng-fei, LI Xiu-ping, JIA Bao-jun, ZHAO Rong-xiang. Preparation of MoO3/g-C3N4 catalyst and its oxidation removal of sulfide in simulated oil[J]. Chem Ind Eng Prog, 2016, 35(12):3934-3941. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=hgjz201612029 [14] MIAO X L, SHEN X P, WU J J, JI Z Y, WANG J H, KONG L R, LIU M M, SONG C S. Fabrication of an all solid Z-scheme photocatalyst g-C3N4/GO/Ag Br with enhanced visible light photocatalytic activity[J]. Appl Catal A:Gen, 2017, 539:104-113. doi: 10.1016/j.apcata.2017.04.009 [15] HUANG L Y, XU H, LI Y P, LI H M, CHENG X N, XIA J X, XU Y G, CAI G B. Visible-light-induced WO3/g-C3N4 composites with enhanced photocatalytic activity[J]. Dalton Trans, 2013, 42(24):8606-8616. doi: 10.1039/c3dt00115f [16] ZHAO Z G, MIYANUCHI M. Nanoporous-walled tungsten oxide nanotubes as highly active visible-light-driven photocatalysts[J]. Angew Chem-Int Ed, 2008, 47(37):7051-7055. doi: 10.1002/anie.v47:37 [17] KHALID N R, AHMED E, HONG Z L, AHMAD M. Synthesis and photocatalytic properties of visible light responsive La/TiO2-graphene composites[J]. Appl Surf Sci, 2012, 263:254-259. doi: 10.1016/j.apsusc.2012.09.039 [18] AMOOZADEH A, RAHMANI S. Nano-WO3-supported sulfonic acid:New efficient and high reusable heterogeneous nanocatalyst[J]. J Mol Catal A:Chem, 2015, 396:96-107. doi: 10.1016/j.molcata.2014.09.020 [19] 桂明生, 王鹏飞, 袁东, 杨易坤. Bi2WO6/g-C3N4复合型催化剂的制备及其可见光光催化性能[J].无机化学学报, 2013, 29(10):2057-2064. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=wjhxxb201310006GUI Ming-sheng, WANG Peng-fei, YUAN Dong, YANG Yi-kun. Preparation of Bi2WO6/g-C3N4 composite catalyst and its visible photocatalytic performance[J]. J Inorg Chem, 2013, 29(10):2057-2064. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=wjhxxb201310006 [20] GAO Y, JIANG P, LIU D F, YUAN H J, YAN X Q, ZHOU Z P, WANG J X, SONG L, LIU L F, ZWOU W Y, WANG C Y, XIE S S. Synthesis, characterization and self-assembly of silver nanowires[J]. Chem Phys Lett, 2003, 380(1):146-149. [21] CHAI B, PENG T, MAO J, LI K, ZAN L. Graphitic carbon nitride (g-C3N4)-Pt-TiO2 nanocomposite as an efficient photocatalyst for hydrogen production under visible light irradiation[J]. Phys Chem Chem Phys, 2012, 14(48):16745-16752. doi: 10.1039/c2cp42484c [22] YANG Y X, GUO Y N, LIU F Y, YUAN X, GUO Y H, ZHANG S Q, GUO W, HUO M X. Preparation and enhanced visible-light photocatalytic activity of silver deposited graphitic carbon nitride plasmonic photocatalyst[J]. Appl Catal B:Environ, 2013, 142/143:828-837. doi: 10.1016/j.apcatb.2013.06.026 [23] ERDEM B, HUNSICKER R A, SIMMONS G W, SUDOL E D, DIMONIE V L, El-AASSER M S. XPS and FT-IR surface characterization of TiO2 particles used polymer encapsulation[J]. Langmuir, 2001, 17(9):2664-2669. doi: 10.1021/la0015213 [24] XUN S H, ZHU W S, CHANG Y H, LI H P, ZHANG M, JIANG W, ZHENG D, QIN Y J, LI H M. Synthesis of supported SiW12O40-based ionic liquid catalyst induced solvent-free oxidative deep-desulfurization of fuels[J]. Chem Eng J, 2016, 288:608-617. doi: 10.1016/j.cej.2015.12.005 [25] CHEN K, ZHANG X M, YANG X F, JIAO M G, ZHOU Z, ZHANG M H, WANG D H, BU X H. Electronic structure of heterojunction MoO2/g-C3N4 catalyst for oxidative desulfurization[J]. Appl Catal B:Environ, 2018, 238:263-273. doi: 10.1016/j.apcatb.2018.07.037 [26] 张黎明, 吴磊, 邵云, 李莲. Cu-g-C3N4/WO3可见光下降解四环素的性能研究[J].人工晶体学报, 2018, 47(6):1128-1135. doi: 10.3969/j.issn.1000-985X.2018.06.007ZHANG Li-ming, WU Lei, SHAO Yun, LI Lei. Study on the properties of Cu-g-C3N4/WO3 degraded tetracycline[J]. J Synth Cryst, 2018, 47(6):1128-1135. doi: 10.3969/j.issn.1000-985X.2018.06.007 [27] 王丽, 赵辉. WO3/N-TiO2异质节可见光催化降解亚甲基蓝[J].工业水处理, 2016, 36(11):78-81. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=gyscl201611018WANG Li, ZHAO Hui. Visible light catalytic degradation of methylene blue by WO3/N TiO2 heterogeneous[J]. Ind Water Treat, 2016, 36(11):78-81. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=gyscl201611018 [28] LI X F, ZHANG J, SHEN L H, MA Y M, LEI W W, CUI Q L, ZOU G T. Preparation and characterization of graphitic carbon nitride through pyrolysis of melamine[J]. Appl Phys A:Mater, 2009, 94(2):387-392. doi: 10.1007/s00339-008-4816-4 [29] LIU H, JIN Z T, XU Z Z, ZHANG Z, AO D. Fabrication of ZnIn2S4-g-C3N4 sheet-on-sheet nanocomposites for efficient visible-light photocatalytic H2-evolution and degradation of organic pollutants[J]. RSC Adv, 2015, 5(119):97951-97961. doi: 10.1039/C5RA17028A [30] KATSUMATA H, TACHI Y, SUZUKI T, KANECO S. Z-scheme photocatalytic hydrogen production over WO3/g-C3N4 composite photocatalysts[J]. RSC Adv, 2014, 4(41):21405-21409. doi: 10.1039/C4RA02511C [31] MA S S, XUE J J, ZHOU Y M, ZHANG Z W. Facile fabrication of mpg-C3N4/TiO2 heterojunction photocatalyst with enhanced visible light photoactivity toward organic pollutant degradation[J]. RSC Adv, 2015, 5(80):64976-64982. doi: 10.1039/C5RA10447E [32] XIAO X, ZHONG H, ZHENG C X, LU M L, ZUO X X, NAN J M. Deep oxidative desulfurization of dibenzothiophene using a flower-like WO3·H2O catalyst in an organic biphasic system[J]. Chem Eng J, 2016, 304:908-916. doi: 10.1016/j.cej.2016.07.022 [33] 卞振锋, 阮大明, 李和兴. Pt负载对TiO2光催化氧化还原的影响[J].中国科技论文, 2016, 11(18):2091-2095. doi: 10.3969/j.issn.2095-2783.2016.18.013BIAN Zhen-feng, RUAN Da-ming, LI He-xing. Effect of Pt loading on photocatalytic REDOX of TiO2[J]. Chin J Sci Technol, 2016, 11(18):2091-2095. doi: 10.3969/j.issn.2095-2783.2016.18.013 -
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