1. School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China 2. School of chemical engineering and textile, Shaanxi Polytechnic Institue, Xianyang 712000, China 3. Xi’an Modern Chemistry Research Institute, Xi’an 710065, China 4. School of Chemistry and Chemical Engineering, Tianjin University of Technology,Tianjin 300384, China
ZnFe2O4-BiOCl composites were prepared by both hydrothermal and direct precipitation processes and the structures and properties of the samples were characterized by various instrumental techniques. The samples were then used as catalysts for the photocatalytic reduction of CO2 in cyclohexanol under ultraviolet irradiation to give cyclohexanone (CH) and cyclohexyl formate (CF). The photocatalytic CO2 reduction activities over the hydrothermally prepared ZnFe2O4-BiOCl composites were higher than those over the directly-precipitated composites. This is because compared to the direct-precipitation sample, the ZnFe2O4 nanoparticles in the hydrothermal sample were smaller and more uniformly distributed on the surface of BiOCl and so more heterojunctions were formed. Higher CF and CH yields were obtained for the pure BiOCl and BiOCl composite samples with more exposed (001) facets than for the samples with more exposed (010) facets. This is due to the higher density of oxygen atoms in the exposed (001) facets, which creates more oxygen vacancies, and thereby improves the separation efficiency of the electron-hole pairs. More importantly, irradiation of the (001) facets with ultraviolet light produces photo-generated electrons which is helpful for the reduction of CO2 to ·CO2–. The mechanism for the photocatalytic reduction of CO2 in cyclohexanol over ZnFe2O4-BiOCl composites with exposed (001) facets involves electron transfer and carbon radical formation.
. [J]. Frontiers of Chemical Science and Engineering, 2017, 11(2): 197-204.
Guixian Song, Xionggang Wu, Feng Xin, Xiaohong Yin. ZnFe2O4 deposited on BiOCl with exposed (001) and (010) facets for photocatalytic reduction of CO2 in cyclohexanol. Front. Chem. Sci. Eng., 2017, 11(2): 197-204.
He Y, Wang Y, Zhang L, Teng B, Fan M. High-efficiency conversion of CO2 to fuel over ZnO/g-C3N4 photocatalyst. Applied Catalysis B: Environmental, 2015, 168: 1–8
2
Ehsan M F, He T. In situ synthesis of ZnO/ZnTe common cation heterostructure and its visible-light photocatalytic reduction of CO2 into CH4. Applied Catalysis B: Environmental, 2015, 166: 345–352 https://doi.org/10.1016/j.apcatb.2014.11.058
3
Habisreutinger S N, Schmidt-Mende L, Stolarczyk J K. Photocatalytic reduction of CO2 on TiO2 and other semiconductors. Angewandte Chemie International Edition, 2013, 52(29): 7372–7408 https://doi.org/10.1002/anie.201207199
4
Liu Y, Zhou S, Li J, Wang Y, Jiang G, Zhao Z, Liu B, Gong X, Duan A, Liu J, Wei Y, Zhang L. Photocatalytic reduction of CO2 with water vapor on surface La-modified TiO2 nanoparticles with enhanced CH4 selectivity. Applied Catalysis B: Environmental, 2015, 168: 125–131 https://doi.org/10.1016/j.apcatb.2014.12.011
5
Liu Q, Zhou Y, Kou J, Chen X, Tian Z, Gao J, Yan S, Zou Z. High-yield synthesis of ultralong and ultrathin Zn2GeO4 nanoribbons toward improved photocatalytic reduction of CO2 into renewable hydrocarbon fuel. Journal of the American Chemical Society, 2010, 132(41): 14385–14387 https://doi.org/10.1021/ja1068596
6
Fan W, Zhang Q, Wang Y. Semiconductor-based nanocomposites for photocatalytic H2 production and CO2 conversion. Physical Chemistry Chemical Physics, 2013, 15(8): 2632–2649 https://doi.org/10.1039/c2cp43524a
7
Richardson P L, Perdigoto M L N, Wang W, Lopes R J G. RETRACTED: Heterogeneous photo-enhanced conversion of carbon dioxide to formic acid with copper-and gallium-doped titania nanocomposites. Applied Catalysis B: Environmental, 2013, 132: 408–415 https://doi.org/10.1016/j.apcatb.2012.11.045
8
Asi M A, He C, Su M, Xia D, Lin L, Deng H, Xiong Y, Qiu R, Li X. Photocatalytic reduction of CO2 to hydrocarbons using AgBr/TiO2 nanocomposites under visible light. Catalysis Today, 2011, 175(1): 256–263 https://doi.org/10.1016/j.cattod.2011.02.055
9
He Z, Wen L, Wang D, Xue Y, Lu Q, Wu C, Chen J, Song S. Photocatalytic reduction of CO2 in aqueous solution on surface-fluorinated anatase TiO2 nanosheets with exposed {001} facets. Energy & Fuels, 2014, 28(6): 3982–3993 https://doi.org/10.1021/ef500648k
10
Xu H, Ouyang S, Li P, Kako T, Ye J. High-active anatase TiO2 nanosheets exposed with 95% {100} facets toward efficient H2 evolution and CO2 photoreduction. ACS Applied Materials & Interfaces, 2013, 5(4): 1348–1354 https://doi.org/10.1021/am302631b
11
Wang W N, Wu F, Myung Y, Niedzwiedzki D M, Im H S, Park J, Banerjee P, Biswas P. Surface engineered CuO nanowires with ZnO islands for CO2 photoreduction. ACS Applied Materials & Interfaces, 2015, 7(10): 5685–5692 https://doi.org/10.1021/am508590j
12
Zhou Y, Tian Z, Zhao Z, Liu Q, Kou J, Chen X, Gao J, Yan S, Zou Z. High-yield synthesis of ultrathin and uniform Bi2WO6 square nanoplates benefitting from photocatalytic reduction of CO2 into renewable hydrocarbon fuel under visible light. ACS Applied Materials & Interfaces, 2011, 3(9): 3594–3601 https://doi.org/10.1021/am2008147
13
Liu Q, Zhou Y, Kou J, Chen X, Tian Z, Gao J, Yan S, Zou Z. High-yield synthesis of ultralong and ultrathin Zn2GeO4 nanoribbons toward improved photocatalytic reduction of CO2 into renewable hydrocarbon fuel. Journal of the American Chemical Society, 2010, 132(41): 14385–14387 https://doi.org/10.1021/ja1068596
14
Chen X, Zhou Y, Liu Q, Li Z, Liu J, Zou Z. Ultrathin, single-crystal WO3 nanosheets by two-dimensional oriented attachment toward enhanced photocatalystic reduction of CO2 into hydrocarbon fuels under visible light. ACS Applied Materials & Interfaces, 2012, 4(7): 3372–3377 https://doi.org/10.1021/am300661s
15
Li X, Liu H, Luo D, Li J, Huang Y, Li H, Fang Y, Xu Y, Zhu L. Adsorption of CO2 on heterostructure CdS (Bi2S3)/TiO2 nanotube photocatalysts and their photocatalytic activities in the reduction of CO2 to methanol under visible light irradiation. Chemical Engineering Journal, 2012, 180: 151–158 https://doi.org/10.1016/j.cej.2011.11.029
16
Li X, Zhuang Z, Li W, Pan H. Photocatalytic reduction of CO2 over noble metal-loaded and nitrogen-doped mesoporous TiO2. Applied Catalysis A, General, 2012, 429: 31–38 https://doi.org/10.1016/j.apcata.2012.04.001
17
Xia J, Xu L, Zhang J, Yin S, Li H, Xu H, Di J. Improved visible light photocatalytic properties of Fe/BiOCl microspheres synthesized via self-doped reactable ionic liquids. CrystEngComm, 2013, 15(46): 10132–10141 https://doi.org/10.1039/c3ce41555d
18
Zhang K, Liang J, Wang S, Liu J, Ren K, Zheng X, Luo H, Peng Y, Zou X, Bo X, Li J, Yu X. BiOCl sub-microcrystals induced by citric acid and their high photocatalytic activities. Crystal Growth & Design, 2012, 12(2): 793–803 https://doi.org/10.1021/cg201112j
19
Zhu L P, Liao G H, Bing N C, Wang L L, Yang Y, Xie H Y. Self-assembled 3D BiOCl hierarchitectures: Tunable synthesis and characterization. CrystEngComm, 2010, 12(11): 3791–3796 https://doi.org/10.1039/c0ce00038h
20
Jiang J, Zhao K, Xiao X, Zhang L. Synthesis and facet-dependent photoreactivity of BiOCl single-crystalline nanosheets. Journal of the American Chemical Society, 2012, 134(10): 4473–4476 https://doi.org/10.1021/ja210484t
21
Li H, Zhang L. Oxygen vacancy induced selective silver deposition on the {001} facets of BiOCl single-crystalline nanosheets for enhanced Cr (VI) and sodium pentachlorophenate removal under visible light. Nanoscale, 2014, 6(14): 7805–7810 https://doi.org/10.1039/c4nr01315h
22
Lin H, Ding L, Pei Z, Zhou Y, Long J, Deng W, Wang X. Au deposited BiOCl with different facets: On determination of the facet-induced transfer preference of charge carriers and the different plasmonic activity. Applied Catalysis B: Environmental, 2014, 160: 98–105 https://doi.org/10.1016/j.apcatb.2014.05.018
23
Fu Y, Wang X. Magnetically separable ZnFe2O4-graphene catalyst and its high photocatalytic performance under visible light irradiation. Industrial & Engineering Chemistry Research, 2011, 50(12): 7210–7218 https://doi.org/10.1021/ie200162a
24
Kong L, Jiang Z, Xiao T, Lu L, Jonesac M O, Edwards Peter P. Exceptional visible-light-driven photocatalytic activity over BiOBr-ZnFe2O4 heterojunctions. Chemical Communications, 2011, 47(19): 5512–5514 https://doi.org/10.1039/c1cc10446b
25
Song G, Xin F, Yin X. Photocatalytic reduction of carbon dioxide over ZnFe2O4/TiO2 nanobeltsheterostructure in cyclohexanol. Journal of Colloid and Interface Science, 2015, 442: 60–66 https://doi.org/10.1016/j.jcis.2014.11.039
26
Yu T H, Cheng W Y, Chao K J, Lu S Y. ZnFe2O4 decorated CdS nanorods as a highly efficient, visible light responsive, photochemically stable, magnetically recyclable photocatalyst for hydrogen generation. Nanoscale, 2013, 5(16): 7356–7360 https://doi.org/10.1039/c3nr02658b
27
Wang M, Sun L, Cai J, Huang P, Su Y, Lin C. A facile hydrothermal deposition of ZnFe2O4 nanoparticles on TiO2 nanotube arrays for enhanced visible light photocatalytic activity. Journal of Materials Chemistry. A, Materials for Energy and Sustainability, 2013, 1(39): 12082–12087 https://doi.org/10.1039/c3ta12577g
28
Guan M, Xiao C, Zhang J, Fan S, An R, Cheng Q, Xie J, Zhou M, Ye B, Xie Y. Vacancy associates promoting solar-driven photocatalytic activity of ultrathin bismuth oxychloride nanosheets. Journal of the American Chemical Society, 2013, 135(28): 10411–10417 https://doi.org/10.1021/ja402956f
29
Zhang X, Wang X B, Wang L W, Wang W K. LongL L, LiW W, Yu H Q. Synthesis of a highly efficient BiOCl single-crystal nanodisk photocatalyst with exposing {001} facets. ACS Applied Materials & Interfaces, 2014, 6(10): 7766–7772
30
Zhang N, Yang M Q, Tang Z R, Xu Y J. CdS-graphene nanocomposites as visible light photocatalyst for redox reactions in water: A green route for selective transformation and environmental remediation. Journal of Catalysis, 2013, 303: 60–69 https://doi.org/10.1016/j.jcat.2013.02.026
31
Song G, Xin F, Chen J, Yin X. Photocatalytic reduction of CO2 in cyclohexanol on CdS-TiO2 heterostructuredphotocatalyst. Applied Catalysis A, General, 2014, 473: 90–95 https://doi.org/10.1016/j.apcata.2013.12.035
32
Ye L, Zan L, Tian L, Peng T, Zhang J. The {001} facets-dependent high photoactivity of BiOCl nanosheets. Chemical Communications, 2011, 47(24): 6951–6953 https://doi.org/10.1039/c1cc11015b
33
Ye L, Deng K, Xu F, Tian L, Peng T, Zan L. Increasing visible-light absorption for photocatalysis with black BiOCl. Physical Chemistry Chemical Physics, 2012, 14(1): 82–85 https://doi.org/10.1039/C1CP22876E
34
Zhang S, Li J, Zeng M, ZhaoG, XuJ, HuW, WangX. In situ synthesis of water-soluble magnetic graphitic carbon nitride photocatalyst and its synergistic catalytic performance. ACS Applied Materials & Interfaces, 2013, 5(23): 12735–12743
