Abstract:Titanium dioxide/graphene (TiO2/G) composite conductive materials were prepared by modified hydrothermal method. The effects of hydrothermal temperature and the amount of graphene on the electrical conductivity of the composites were investigated. The structure, microstructure and conductivity of the composites were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and so on, and the optimum hydrothermal temperature and the optimum doping amount of graphene were determined. The results show that the electrical conductivity of TiO2/G is the best when the content of graphene is 5% (mass fraction), the hydrothermal temperature is 160℃, and its resistivity is 13.46Ω·cm. The nano TiO2 in the composite is a spherical anatase phase with a diameter of about 100-200nm, and it is grown uniformly on the lamellar surface of graphene. Among them, the nano TiO2 is grown on the graphene layers, which effectively prevents the agglomeration of the graphene layer, which is beneficial to the formation of conductive network between the graphene layers, improves the efficiency of electron migration, and endows the titanium dioxide composites with excellent electrical conductivity.
[1] 汪静茹,李文尧,姚宝殿. 水热法制备二氧化钛纳米管:形成机理、影响因素及应用[J]. 材料导报, 2016, 30(5):144-152. WANG J R, LI W Y, YAO B D. Hydrothermally produced titania nanotubes:formation mechanism, influence factorsand applications[J]. Materials Review, 2016, 30(5):144-152.
[2] HU J, LI H S, MUHAMMAD S, et al. Surfactant-assisted hydrothermal synthesis of TiO2/reduced graphene oxide nanoco-mposites and their photocatalytic performances[J]. Journal of Solid State Chemistry, 2017, 253:113-120.
[3] TACHIKAWA T, MINOHARA M, HIKITA Y, et al. Tuning band alignment using interface dipoles at the Pt/anatase TiO2 interface[J]. Advanced Materials, 2015, 27(45):7458-7461.
[4] CHEN B, MENG Y H, SHA J W, et al. Preparation of MoS2/TiO2 based nanocomposites for photocatalysis and rechargeable batteries:progress, challenges, and perspective[J]. Nanoscale, 2017, 10(4):34-68.
[5] ZHANG L X, ZHANG J, JIU H F, et al. Graphene-based hollow TiO2 composites with enhanced photocatalytic activity for removal of pollutants[J]. Journal of Physics and Chemistry of Solids, 2015, 86:82-89.
[6] GAN Z, WU X, MENG M, et al. Photothermal contribution to enhanced photocatalytic performance of graphene-based nanocomposites[J]. ACS Nano, 2014, 8(9):9304-9310.
[7] GU W L, LU F X, WANG C, et al. Face-to-face interfacial assembly of ultrathin g-C3N4 and anatase TiO2 nanosheets for enhanced solar photocatalytic activity[J]. ACS Applied Materials & Interfaces, 2017, 9(34):28674-28684.
[8] ZHANG Z, REN L, HAN W J, et al. One-pot electrodeposition synthesis of ZnO/graphene composite and its use as binder-free electrode for supercapacitor[J]. Ceramics International, 2015, 41(3):4374-4380.
[9] ZHENG C C, HE C H, ZHANG H Y, et al. TiO2-reduced graphene oxide nanocomposite for high-rate application of lithium ion batteries[J]. Ionics, 2014, 21(1):51-58.
[10] WANG H M, YAN Y, CHEN G. Integrating the hierarchical structure with well-dispersed conductive agents to realize synerg-istically enhanced electrode performance[J]. Journal of Materials Chemistry A, 2015, 3(19):10275-10283.
[11] RAMACHANDRAN R, MANI V, CHEN S M, et al. Recent trends in graphene based electrode materials for energy storage devices and sensors applications[J]. International Journal of Electrochemical Science, 2013, 8(8):11680-11694.
[12] 刘志彬. 二氧化钛-表面活性剂处理甲基橙的性能研究[J]. 哈尔滨商业大学学报(自然科学版), 2015, 31(2):177-182. LIU Z B. Research of removal methyl orange by titanium diox-ide-surfactant[J]. Journal of Harbin University of Commerce (Natural Sciences Edition), 2015, 31(2):177-182.
[13] 龙梅,丛野,李轩科,等. 部分还原氧化石墨烯/二氧化钛复合材料的水热合成及其光催化活性[J]. 物理化学学报, 2013, 29(6):1344-1350. LONG M, CONG Y, LI X K, et al. Hydrothermal synthesis and photocatalytic activity of partially reduced graphene oxide/TiO2 composite[J]. Acta Physico-Chimica Sinica, 2013, 29(6):1344-1350.
[14] LI K, GAO S M, WANG Q Y, et al. In-situ-reduced synthesis of Ti3+ self-doped TiO2/g-C3N4 heterojunctions with high photocatalytic performance under LED light irradiation[J]. ACS Applied Materials & Interfaces, 2015, 7(17):9023-9030.
[15] SHEN H L, CUI C, YING B L, et al. One-step hydrothermal synthesis of anatase TiO2/reduced graphene oxide nanocompo-sites with enhanced photocatalytic activity[J]. Journal of Alloys & Compounds, 2014, 582(1):236-240.
[16] SHEN J F, SHI M, YAN B, et al. Ionic liquid-assisted one-step hydrothermal synthesis of TiO2-reduced graphene oxide compo-sites[J]. Nano Research, 2011, 4(8):795-806.
[17] LAVRIC V, ISOPESCU R, MAURINO V, et al. A new model for nano-TiO2 crystals birth and growth in hydrothermal treat-ment using oriented attachment approach[J]. Crystal Growth & Design, 2017, 17(11):5640-5651.
[18] JIANG G O, LIN Z F, CHEN C, et al. TiO2 nanoparticles assembled on graphene oxide nanosheets with high photocatalytic activity for removal of pollutants[J]. Carbon, 2011, 49(8):2693-2701.
[19] LIU J, BAI H, WANG Y, et al. Self-assembling TiO2 nanorods on large graphene oxide sheets at a two-phase interface and their anti-recombination in photocatalytic applications[J]. Advanced Functional Materials, 2010, 20(23):4175-4181.
[20] STANKOVICH S, DIKIN D A, PINER R D, et al. Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide[J]. Carbon, 2007, 45(7):1558-1565.
[21] ZHANG Y, TANG Z R, FU X, et al. Engineering the unique 2D mat of graphene to achieve graphene-TiO2 nanocomposite for photocatalytic selective transformation:what advantage does graphene have over its forebear carbon nanotube[J]. ACS Nano, 2011, 5(9):7426-7435.
[22] WU N Q, FU L, SU M, et al. Interaction of fatty acid mon-olayers with cobalt nanoparticles[J]. Nano Letters, 2015, 4(2):383-386.
[23] HE J J, WU D P, GAO Z Y, et al. Graphene sheets anchored with high density TiO2 nanocrystals and their application in quantum dot-sensitized solar cells[J]. RSC Advances, 2013, 4(4):2068-2072.