Abstract: Mixed metal oxides ZnO/ZnAl2O4(ZnAl-MMO) with heterojunction structure were fabricated by thermal treatment of precursor of ZnAl-LDH at high temperature. All obtained samples were analysed by X ray diffraction (XRD), scanning elctron microscopy (SEM), transmission electron microscopy(TEM), specific surface specific aperture and UV-Vis diffuse reflectance. The function of pH solution, initial Cr(Ⅵ) concentration and the hole scavenger citric acid (CA) concentration on the photocatalytic performance were further discussed. An increase in the Cr (Ⅵ) photoreduced with decreasing pH values was noticed, suggesting that significance of pH values on phtoreduction. CA can adjust the pH of solution which improve the photocatalytic largely, furthermore, it can catch the holes effectively that leading to a better photocatalytic performance.
1 Chuang Y H, Yu M T, Wang M K, et al. Removal of 2-chlorophenol from aqueous solution by Mg/Al layered double hydroxide (LDH) and modified LDH[J]. Industrial & Engineering Chemistry Research,2008,47(11):3813. 2 Corma A, Palomares A E, Rey F, et al. Simultaneous catalytic removal of SOx and NOx with hydrotalcite-derived mixed oxides containing copper, and their possibilities to be used in FCC units[J]. Journal of Catalysis,1997,170(1):140. 3 Shannon I J, Maschmeyer T, Sankar G, et al. A new cell for the collection of combined EXAFS/XRD data in situ during solid/liquid catalytic reactions[J]. Catalysis Letters,1997,44(1-2):23. 4 Kannan S. Decomposition of nitrous oxide over the catalysts derived from hydrotalcite-like compounds[J]. Applied Clay Science,1998,13(5):347. 5 Kannan S, Swamy C S. Catalytic decomposition of nitrous oxide over calcined cobalt aluminum hydrotalcites[J]. Catalysis Today,1999,53(4):725. 6 Palomares A E, López-Nieto J M, Lázaro F J, et al. Reactivity in the removal of SO2, and NOx, on Co/Mg/Al mixed oxides derived from hydrotalcites[J]. Applied Catalysis B Environmental,1999,20(4):257. 7 Palomares A E, Prato J G, Rey F, et al. Using the “memory effect” of hydrotalcites for improving the catalytic reduction of nitrates in water[J]. Journal of Catalysis,2004,221(1):62. 8 Xia S, Zhang L, Pan G, et al. Photocatalytic degradation of methy-lene blue with a nanocomposite system: Synthesis, photocatalysis and degradation pathways[J]. Physical Chemistry Chemical Physics,2015,17(7):5345. 9 Rahman M B A, Basri M, Hussein M Z, et al. Immobilisation of lipase from Candida rugosa on layered double hydroxides of Mg/Al and its nanocomposite as biocatalyst for the synthesis of ester[J]. Catalysis Today,2004,93(1):405. 10 Yuan X, Wang Y, Wang J, et al. Calcined graphene/MgAl-layered double hydroxides for enhanced Cr(Ⅵ) removal[J]. Chemical Engineering Journal,2013,221(2):204. 11 Nickens K P, Patierno S R, Ceryak S. Chromium genotoxicity: A double-edged sword[J]. Chemico-biological Interactions,2010,188(2):276. 12 Wang Q, Shang J, Song H. Photoelectrocatalytic reduction of Cr(Ⅵ) over TiO2 nanotube arrays under half-wave pulsed direct current[J]. Acta Chimica Sinica,2012,70(4):405(in Chinese). 汪青,尚静,宋寒. TiO2纳米管半波脉冲直流电光电催化还原Cr(Ⅵ)[J].化学学报,2012,70(4):405. 13 Schrank S G, José H J, Moreira R F P M. Simultaneous photocatalytic Cr(Ⅵ) reduction and dye oxidation in a TiO2, slurry reactor[J]. Journal of Photochemistry & Photobiology A Chemistry,2002,147(1):71. 14 Costa M. Potential hazards of hexavalent chromate in our drinking water[J]. Toxicology & Applied Pharmacology,2003,188(1):1. 15 Hu X, Ji H, Chang F, et al. Simultaneous photocatalytic Cr(Ⅵ) reduction and 2,4,6-TCP oxidation over g-C3N4, under visible light irradiation[J]. Catalysis Today,2014,224(4):34. 16 Yuan X, Li W. Graphitic-C3N4, modified ZnAl-layered double hydroxides for enhanced photocatalytic removal of organic dye[J]. Applied Clay Science,2017,138:107. 17 Goh K H, Lim T T, Dong Z. Application of layered double hydro-xides for removal of oxyanions: A review[J]. Water Research,2008,42(6):1343. 18 Evans D G, Slade R C T. Structural aspects of layered double hydroxides[M]∥Layered Double Hydroxides. Berlin Heidelberg:Springer,2006:1. 19 Guan M Y, Xu D M, Song Y F, et al. ZnO/ZnAl2O4, prepared by calcination of ZnAl layered double hydroxides for ethanol sensing[J]. Sensors & Actuators B Chemical,2013,188:1148. 20 Cavani F, Trifirò F, Vaccari A. Hydrotalcite-type anionic clays: Preparation, properties and applications[J]. Catalysis Today,1991,11(2):173. 21 Das N N, Konar J, Mohanta M K, et al. Adsorption of Cr(Ⅵ) and Se(Ⅳ) from their aqueous solutions onto Zr4+-substituted ZnAl/MgAl-layered double hydroxides: Effect of Zr4+substitution in the layer[J]. Journal of Colloid & Interface Science,2004,270(1):1. 22 Vaccari A. Preparation and catalytic properties of cationic and anio-nic clays[J]. Catalysis Today,1998,41(1-3):53. 23 Zhao X, Zhang F, Xu S, et al. From layered double hydroxides to ZnO-based mixed metal oxides by thermal decomposition: Transformation mechanism and UV-blocking properties of the product[J]. Chemistry of Materials,2010,22(13):3933. 24 Yuan X, Jing Q, Chen J, et al. Photocatalytic Cr(Ⅵ) reduction by mixed metal oxide derived from ZnAl layered double hydroxide[J]. Applied Clay Science,2017,143:168. 25 Chen C X, Yi W Z, Yang C L, et al. the study of decolorization of methylene blue by SDS-MgnAl-LDO[J]. Materials Review,2012,26(S1):314(in Chinese). 陈春霞,易武中,杨春丽,等.SDS-MgnAl-LDO对亚甲基蓝的脱色研究[J].材料导报,2012,26(专辑19):314. 26 Das D P, Das J, Parida K. Physicochemical characterization and adsorption behavior of calcined Zn/Al hydrotalcite-like compound (HTlc) towards removal of fluoride from aqueous solution[J]. Journal of Colloid & Interface Science,2003,261(2):213. 27 Qin F, Yu X Y, Jiang Q F, et al. Adsorption removal of humic acid by Mg/Al hydrotalcite[J]. Materials Review B: Research Papers,2015,29(8):79(in Chinese). 秦芳,喻杏元,蒋钦凤,等.Mg/Al水滑石对腐殖酸的去除性能研究[J].材料导报:研究篇,2015,29(8):79. 28 Li C, Wei M, Evans D G, et al. Layered double hydroxide-based nanomaterials as highly efficient catalysts and adsorbents[J]. Small,2014,10(22):4469. 29 Cho S, Lee K H. Formation of zinc aluminum mixed metal oxide nanostructures[J]. Journal of Alloys & Compounds,2011,509(35):8770. 30 Costantino U, Natascia Coletti A, Nocchetti M, et al. Anion exchange of methyl orange into Zn-Al synthetic hydrotalcite and photophysical characterization of the intercalates obtained[J]. Langmuir,1999,15(13):4454. 31 Pfeiffer H, Lima E, Lara V, et al. Thermokinetic study of the rehydration process of a calcined MgAl-layered double hydroxide[J]. Langmuir,2010,26(6):4074. 32 Tian X D, Li X, Yang T, et al. Recent advances on synthesis and supercapacitor application of binary metal oxide[J]. Journal of Inorganic Materials,2017,32(5):459(in Chinese). 田晓东,李肖,杨桃,等.双金属氧化物和复合材料的合成及其在超级电容器中的应用进展[J].无机材料学报,2017,32(5):459. 33 Zhao X, Lei W, Xin X, et al. Fabrication and photocatalytic properties of novel ZnO/ZnAl2O4 nanocomposite with ZnAl2O4 dispersed inside ZnO network[J]. Aiche Journal,2012,58(2):573. 34 Zheng Y M, Li N, Zhang W D. Preparation of nanostructured microspheres of Zn-Mg-Al layered double hydroxides with high adsorption property[J]. Colloids & Surfaces A Physicochemical & Engineering Aspects,2012,415(48):195. 35 Reichle W T, Kang S Y, Everhardt D S. The nature of the thermal decomposition of a catalytically active anionic clay mineral[J]. Journal of Catalysis,1986,101(2):352. 36 Zhang L, Liu J, Xiao H, et al. Preparation and properties of mixed metal oxides based layered double hydroxide as anode materials for dye-sensitized solar cell[J]. Chemical Engineering Journal,2014,250(250):1. 37 Ibhadon A O, Greenway G M, Yue Y, et al. The photocatalytic activity and kinetics of the degradation of an anionic azo-dye in a UV irradiated porous titania foam[J]. Applied Catalysis B Environmental,2008,84(3-4):351. 38 Boclair J W, Braterman P S. Layered double hydroxide stability. 1. Relative stabilities of layered double hydroxides and their simple counterparts[J]. Chemistry of Materials A Publication of the American Chemical Society,1999,11(2):298. 39 Yang L, Xiao Y, Liu S, et al. Photocatalytic reduction of Cr(Ⅵ) on WO3 doped long TiO2 nanotube arrays in the presence of citric acid[J]. Applied Catalysis B Environmental,2010,94(1):142. 40 Mondal C, Ganguly M, Pal J, et al. Morphology controlled synthesis of SnS2 nanomaterial for promoting photocatalytic reduction of aqueous Cr(Ⅵ) under visible light[J]. Langmuir,2014,30(14):4157.
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2018, Vol. 32 
