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ZnO/TiO2 Nanocomposite Synthesized by Sol Gel from Highly Soluble Single Source Molecular Precursor
Hameed Ullah*,Kabeer Ahmad Khan,Wasid Ullah Khan
Author NameAffiliationE-mail
Hameed Ullah* Department of Chemistry, Hazara University, Mansehra, KPK, Pakistan hameedwazir@yahoo.co.uk 
Kabeer Ahmad Khan Department of Chemistry, Hazara University, Mansehra, KPK, Pakistan  
Wasid Ullah Khan Department of Chemistry, Hazara University, Mansehra, KPK, Pakistan  
Abstract:
Single source molecular precursors (SSPs) provide an opportunity to get control over the microstructure of nanomaterials at atomic level. A SSP was designed and developed for the synthesis of ZnO/TiO2 nanocomposite by sol gel method. In a typical synthe-sis process, a bimetallic molecular compound with chemical formula [Cl2TiZn(dmae)4] (dmae=dimethylaminoethanol) was synthesized and its chemical composition was deter-mined by elemental analysis. The obtained compound has shown excellent solubility in common organic solvents, a prerequisite for its use in sol gel method as SSP. The SSP ob-tained was controllably hydrolyzed by adding equimolar amount of water using ethanol as solvent to get ZnO/TiO2 nanocomposite gel. The resulting gel was precipitated at pH=9 and sintered at 200 oC (T200), 400 oC (T400), and 600 oC (T600). The XRD analyses have shown that the as synthesized (non-sintered, T00) powder was amorphous. However, the crystallinity improved upon sintering, and the XRD analyses revealed that the resulting nanomaterials were composed of mixed oxides i.e., ZnO and TiO2. The ZnO was in wurtzite (hexagonal) while the TiO2 was in brookite (orthorhombic) phase. The increase in particlesize was further confirmed from BET analysis and SEM micrographs. The IR spectra ob-tained for the resulting powder have shown the peculiar vibrational bands for Zn-O and Ti-O. Furthermore, the IR spectra revealed that the non-sintered ZnO/TiO2 nanocomposite had significant number of OH group which was removed upon sintering. The photocatalytic activities of the ZnO/TiO2 nanocomposites were tested. All the samples have shown good photocatalytic activities. However, the T400 has shown higher activity than the T00, T200, and T600. The higher photocatalytic activity of T400 than T00, T200, and T600 may be due to improved crystallinity which ensures efficient grain boundary interfaces.
Key words:  Single source precursor, Sol gel, ZnO/TiO2, Methyl orange, Photocatalytic activity
FundProject:
从可溶性单源分子前驱体采用溶胶凝胶法制备ZnO/TiO2 纳米复合物
Hameed Ullah*,Kabeer Ahmad Khan,Wasid Ullah Khan
摘要:
合成了单源分子前驱体Cl2TiZn(dmae)4 (dmae为2-二甲基乙醇胺),并以乙醇为溶剂,加入等摩尔量的水对其进行可控水解得ZnO/TiO2纳米复合凝胶,经pH=9沉淀,在200、400和600 oC 烧结得到不同的产物T200、T400、T600. XRD分析表明未烧结产物为无定形粉末并随着烧结温度升高晶型改善. ZnO呈纤锌矿结构(六方晶系),TiO2呈板钛矿型结构(正交). BET分析和扫描电镜表明颗粒的大小随着烧结温度的提高而增加. 红外光谱证明Zn-O和Ti-O的特有的振动频率,OH基团烧结后的产物中被去掉. 所有的样品都显示良好的光催化活性, 且T600活性最高.
关键词:  单源分子前驱体,溶胶凝胶法,ZnO/TiO2,甲基橙,光催化活性
DOI:10.1063/1674-0068/27/05/548-554
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