Preparation and photocatalytic reduction performance of 2D SnO2/C3N4 composite photocatalyst
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摘要: 可见光响应型二维复合半导体材料是光催化领域研究的重要内容,构建稳定有效的异质结以促进界面电荷传输是二维复合材料研究的关键。将氮化碳纳米片(C3N4)和SnO2纳米片通过煅烧法设计合成面-面堆叠式2D-2D SnO2/C3N4复合半导体。该复合材料保留稳定的C3N4和SnO2的主体结构,同时在界面处形成稳定的异质结。光解水制氢(H2)和活化氧(O2)制过氧化氢(H2O2)的性能测试结果表明,在可见光照射下,SnO2纳米片含量为5wt%的复合样品SnO2/C3N4-5%具有显著提升的制H2活性(54.9 µmol·h−1),约是C3N4纳米片的2.1倍,且具有良好的活性稳定性;在无牺牲剂和助催化剂条件下,SnO2/C3N4-5%活化O2制H2O2的活性达78.9 µmol·L−1·h−1,约是C3N4纳米片的11.9倍。结构表征及电化学测试结果表明,异质结的建立有利于C3N4光生电子向SnO2表面快速转移,抑制了激发电子空穴的复合率,从而大幅提升了光催化还原性能。Abstract: Visible-light responsive two-dimensional composite semiconductor materials are significant in the field of photocatalysis. Construction of stable and effective heterojunctions to promote interface charge transport is the key in the research of two-dimensional composite materials. In this work, a face-to-face stacked 2D-2D SnO2/C3N4 composite semiconductor was synthesized by calcining carbon nitride (C3N4) nanosheets and SnO2 nanosheets. The main structure of C3N4 and SnO2 well stably retained and a stable heterojunction at the interface of them was formed. Photocatalytic test results of water splitting for hydrogen (H2) evolution and active oxygen (O2) for hydrogen peroxide (H2O2) generation show that under visible light irradiation, the composite sample of SnO2/C3N4-5% while the content of SnO2 is 5wt% shows much enhanced H2 evolution activity (54.9 µmol·h−1), which is about 2.1 times as that of C3N4 nanoseets. And the H2O2 generation activity of SnO2/C3N4-5% is 78.9 µmol·L−1·h−1, which is about 11.9 times that of C3N4 nanosheets. The structural characterization and electrochemical tests show that the establishment of heterojunction facilitate the rapid transfer of photogenerated electrons from C3N4 to SnO2, inhi-bite the recombination rate of excited electrons-holes, and greatly improve the photocatalytic reduction perfor-mance.
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Key words:
- C3N4 /
- SnO2 /
- heterojunction /
- water splitting for H2 evolution /
- hydrogen peroxide
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图 7 C3N4、SnO2和SnO2/C3N4产H2活性图 (a),SnO2/C3N4-5%连续产H2活性图 (b),C3N4、SnO2和SnO2/C3N4在O2氛围下制H2O2活性图 (c) 及4 h制H2O2活性比较图 (d)
Figure 7. Photocatalytic H2 production of C3N4, SnO2 and SnO2/C3N4 (a), continuous H2 production of SnO2/C3N4-5% (b), continuous H2O2 production of C3N4, SnO2 and SnO2/C3N4 under oxygen conditions (c) and H2O2 production after 4 h illumination (d)
SnO2/C3N4-5M—Mechanical mixing of SnO2 and C3N4 with a mass ratio of 5wt%
图 8 SnO2和C3N4纳米片的莫特-肖特基曲线 ((a), (b)) 及光照下SnO2/C3N4异质结界面电荷转移机制图 (c)
Figure 8. Mott-Schottky plots of SnO2 and C3N4 nanosheets ((a), (b)), charge transfer mechanism of SnO2/C3N4 heterojunction under illumination (c)
C—Interfacial capacitance; SCE—Saturated calomel electrode; SHE—Standard hydrogen electrode; F—Faraday constant
表 1 SnO2/C3N4复合物的合成配比及命名
Table 1. Synthesis ratio and naming of SnO2/C3N4 compounds
Sample C3N4/g SnO2/g SnO2/C3N4-1%
SnO2/C3N4-3%
SnO2/C3N4-5%
SnO2/C3N4-7%
SnO2/C3N4-10%0.5
0.5
0.5
0.5
0.50.005
0.015
0.025
0.035
0.050 -
[1] BONACCORSO F, COLOMBO L, YU G H, et al. 2D Materials. Graphene, related two-dimensional crystals, and hybrid systems for energy conversion and storage[J]. Science,2015,347(6271):1246501. [2] MENG S G, CHEN C, GU X M. Efficient photocatalytic H2 evolution, CO2 reduction and N2 fixation coupled with organic synthesis by cocatalyst and vacancies engineering[J]. Applied Catalysis B: Environmental, 2021, 285: 119789. [3] CHEN X J, WANG J, CHAI Y Q, et al. Efficient photocataly-tic overall water splitting induced by a giant internal electric field of g-C3N4/rGO/PDIP Z-scheme heterojunction[J]. Advanced Materials, 2021, 33(7): 2007479. [4] WANG M, TAN G Q, DANG M Y, et al. Dual defects and build-in electric field mediated direct Z-scheme W18O49/g-C3N4 heterojunction for photocatalytic NO removal and organic pollutant degradation[J]. Journal of Colloid and Interface Science,2021,582:212-226. doi: 10.1016/j.jcis.2020.08.040 [5] FANG Y X, FU X Z, WANG X C. Diverse polymeric carbon nitride-based semiconductors for photocatalysis and variations[J]. ACS Materials Letters, 2020, 2(8): 975-980. [6] 崔言娟, 王愉雄, 王浩, 等. 石墨相氮化碳的改性剂在环境净化中的应用[J]. 化学进展, 2016, 28(4):428-437.CUI Yanjuan, WANG Yuxiong, WANG Hao, et al. Graphitic carbon nitrides: Modifications and applications in environmental purification[J]. Progress in Chemistry,2016,28(4):428-437(in Chinese). [7] 梁红玉, 邹赫, 胡绍争, 等. 二元碱金属共掺杂石墨相氮化碳的制备及光催化性能评价[J]. 材料导报, 2018, 32(24):10-16.LIANG Hongyu, ZHOU He, HU Shaozheng, et al. Preparation and photocatalytic performance evaluation of carbon nitride in graphite phase Co-doped with binary alkali metal[J]. Materials Reports,2018,32(24):10-16(in Chinese). [8] LIN B, XUE C, YAN X, et al. Facile fabrication of novel SiO2/g-C3N4 core-shell nanosphere photocatalysts with enhanced visible light activity[J]. Applied Surface Science,2015,357:346-355. doi: 10.1016/j.apsusc.2015.09.041 [9] ZHAO S, WU J B, WANG Z P, et al. Ag2CO3-derived Ag/g-C3N4 composite with enhanced visible-light photocatalytic activity for hydrogen production from water splitting[J]. International Journal of Hydrogen Energy,2020,45(41):20851-20858. doi: 10.1016/j.ijhydene.2020.05.191 [10] LUO J H, LIN Z X, ZHAO Y, et al. The embedded CuInS2 into hollow-concave carbon nitride for photocatalytic H2O splitting into H2 with S-scheme principle[J]. Chinese Journal of Catalysis,2020,41(1):122-130. doi: 10.1016/S1872-2067(19)63490-X [11] XU Q L, ZHU B C, JIANG C J, et al. Constructing 2D/2D Fe2O3/g-C3N4 direct Z-scheme photocatalysts with enhanced H2 generation performance[J]. Solar RRL,2018,2(3):1800006. doi: 10.1002/solr.201800006 [12] LI Y H, GU M L, ZHANG X M, et al. 2D g-C3N4 for advancement of photo-generated carrier dynamics: Status and challenges[J]. Materials Today, 2020, 41: 270-303. [13] 李俊怡, 梁峰, 田亮, 等. 类石墨相氮化碳纳米片的制备研究进展[J]. 化学通报, 2018, 81(5): 387-393.LI Junyi, LIANG Feng, TIAN Liang, et al. Progress in preparation method of g-C3N4 nanosheets[J]. Chemistry, 2018, 81(5): 387-393(in Chinese). [14] 孟培媛, 郭明媛, 乔勋. WS2/g-C3N4 异质结光催化分解水制氢性能及机制[J]. 复合材料学报, 2021, 38(2):581-600.MENG Peiyuan, GUO Mingyuan, QIAO Xun. H2 production performance of photocatalyst and mechanism of WS2/g-C3N4 heterojunction[J]. Acta Materiae Composite Sinica,2021,38(2):581-600(in Chinese). [15] WANG X J, TIAN X, SUN Y J, et al. Enhanced schottky effect of a 2D-2D CoP/g-C3N4 interface for photocatalytic H2 evolution[J]. Nanoscale,2018,10(26):12315-12321. doi: 10.1039/C8NR03846E [16] ONG W J. 2D/2D graphitic carbon nitride (g-C3N4) heterojunction nanocomposites for photocatalysis: Why does face-to-face interface matter[J]. Frontiers in Materials, 2017, 4: 11. [17] WANG M, SHEN M, ZHANG L X, et al. 2D-2D MnO2/g-C3N4 heterojunction photocatalyst: In-situ synthesis and enhanced CO2 reduction activity[J]. Carbon,2017,120:23-31. doi: 10.1016/j.carbon.2017.05.024 [18] PAN T, CHEN D D, XU W C, et al. Anionic polyacrylamide-assisted construction of thin 2D-2D WO3/g-C3N4 step-scheme heterojunction for enhanced tetracycline degradation under visible light irradiation[J]. Journal of Hazar-dous Materials,2020,393:122366. doi: 10.1016/j.jhazmat.2020.122366 [19] PUGA F, NAVĺO J A, HIDALGO M C. Enhanced UV and visible light photocatalytic properties of synthesized AgBr/SnO2 composites[J]. Separation and Purification Technology,2021,257:117948. doi: 10.1016/j.seppur.2020.117948 [20] MANJUNATHA A S, PAVITHRA N S, SHIVANNA M, et al. Synthesis of citrus limon mediated SnO2-WO3 nanocomposite: Applications to photocatalytic activity and electrochemical sensor[J]. Journal of Environmental Chemical Engineering,2020,8(6):104500. doi: 10.1016/j.jece.2020.104500 [21] ZANG Y Z, LI L P, LI X G, et al. Synergistic collaboration of g-C3N4/SnO2 composites for enhanced visible-light photocatalytic activity[J]. Chemical Engineering Journal,2014,246(15):277-286. [22] JI H Y, FAN Y M, XU Y G, et al. Construction of SnO2/graphene-like g-C3N4 with enhanced visible light photocatalytic activity[J]. RSC Advances,2017,7(57):36101. doi: 10.1039/C7RA05830F [23] WANG X Q, HE Y, XU L, et al. SnO2 particles as efficient photocatalysts for organic dye degradation grown in-situ on g-C3N4 nanosheets by microwave-assisted hydrother-mal method[J]. Materials Science in Semiconductor Processing,2021,121:105298. doi: 10.1016/j.mssp.2020.105298 [24] WANG L C, CAO S, GUO K, et al. Simultaneous hydrogen and peroxide production by photocatalytic water splitting[J]. Chinese Journal of Catalysis,2019,40(3):470-475. doi: 10.1016/S1872-2067(19)63274-2 [25] 谷龙艳, 氧健康, 候兴凯, 等. 一步法制备纳米SnO-SnO2复合材料及其光催化性能增强机制的光生载流子动力学[J]. 复合材料学报, 2018, 35(10):2624-2631.GU Longyan, YANG Jiankang, HOU Xingkai, et al. One step synthesis of nano SnO-SnO2 composites and the photoinduced charge carrier dynamics for the enhanced photocatalytic performance[J]. Acta Materiae Compositae Sinica,2018,35(10):2624-2631(in Chinese). [26] ZHANG C, ZHOU Y, BAO J, et al. Structure regulation of ZnS@g-C3N4/TiO2 nanospheres for efficient photocataly-tic H2 production under visible-light irradiation[J]. Che-mical Engineering Journal,2018,46(15):226-237. [27] JOURSHABANI M, SHARIATINIA Z, BADIEI A. In situ fabrication of SnO2/S-doped g-C3N4 nanocomposites and improved visible light driven photodegradation of methylene blue[J]. Journal of Molecular Liquids,2017,248:688-702. doi: 10.1016/j.molliq.2017.10.110 [28] RANJITHKUMAR R, LAKSHMANAN P, DEVENDRAN P, et al. Investigations on effect of graphitic carbon nitride loading on the properties and electrochemical perfor-mance of g-C3N4/TiO2 nanocomposites for energy storage device applications[J]. Materials Science in Semiconduc-tor Processing,2021,121:105328. doi: 10.1016/j.mssp.2020.105328 [29] LIU H J, DU C W, LI M, et al. One-pot hydrothermal synthesis of SnO2/BiOBr heterojunction photocatalysts for the efficient degradation of organic pollutants under visible light[J]. ACS Applied Materials & Interfaces,2018,10(34):28686-28694. [30] ZHANG H Q, YANG J X, GUO L, et al. Microwave-aided synthesis of BiOI/g-C3N4 composites and their enhanced catalytic activities for Cr(VI) removal[J]. Chemical Physics Letters,2021,762:138143. doi: 10.1016/j.cplett.2020.138143 [31] WANG Y X, WANG H, CHEN F Y, et al. Facile synthesis of oxygen doped carbon nitride hollow microsphere for photocatalysis[J]. Applied Catalysis B: Environmental,2017,206:417-425. doi: 10.1016/j.apcatb.2017.01.041 [32] DANISH M, MUNEER M. Novel ZnSQDs-SnO2/g-C3N4 nanocomposite with enhanced phtocatalytic performance for the degradation of different organic pollutants in aqueous suspension under visible light[J]. Journal of Physics and Chemistry of Solids, 2021, 149: 109785. [33] ZHU C, ZHU M M, SUN Y, et al. Carbon-supported oxygen vacancy-rich Co3O4 for robust photocatalytic H2O2 production via coupled water oxidation and oxygen reduction reaction[J]. ACS Applied Energy Materials,2019,2:8737-8746. doi: 10.1021/acsaem.9b01712 [34] ZHU Y X, CUI Y J, XIAO B B, et al. Z-scheme 2D/2D g-C3N4/Sn3O4 heterojunction for enhanced visible-light photocatalytic H2 evolution and degradation of ciprofloxacin[J]. Materials Science in Semiconductor Processing,2021,129:105767. doi: 10.1016/j.mssp.2021.105767