Zn-containing Hybrid Metal Organic Precursores and Derived Doped ZnO Nanostructures: Synthesis Properties and Application in Gas Sensing and Photocatalyst

Abstract

A series of Metal Organic precursors (MOPs) were synthesized structure determination found out metal-ligand complex follows our proposal The main objective of this study was to synthesize and characterize precursors that are capable of producing zinc/copper precursors with varity ratio of zinc/copper the researcher studied Cu doped ZnO via these precursors by thin films and chemical vapor deposition (CVD) Metal Organic Precursors (MOPs) are often volatile enough to be useful as precursors of the metals in vapor phase deposition process e g chemical vapor deposition (CVD) MOPs materials have been a focus of researchers for their applications as molecular storage molecular sensing catalysis asymmetric synthesis and host materials MOPs represent a promising new class of crystalline solids because they exhibit large pore volumes high surface areas permanent porosity high thermal stability and feature open channels with tunable dimensions and topology In this study we investigated the design synthesis and structures of a new family of MOPs Here we present our effort in continuing MOPs precursors design and synthesis to expand our knowledge about MOPs family In chapter 1 MOPs precursors and metals doped ZnO with the application are introduced In chapter 2 we synthesized organic hybrid novel metal mixed compounds of bis (acetylacetonato κ-O O') [zinc (II)/copper (II)] Taking C10H14O4Zn0 7Cu0 3 (Z0 7C0 3AA) as an example the crystals are composed of Z0 7C0 3AA units and uncoordinated water molecules Single-crystal X-ray diffraction results show that the complex Z0 7C0 3AA crystallizes in the monoclinic system space group P21/n The unit cell dimensions are a = 10 329(4) ? b = 4 6947(18) ? and c = 11 369(4) ?; the angles are ? = 90° β = 91 881(6) ° and γ = 90° the volume is 551 0(4) ?3 and Z = 2 In this process the M (II) ions of Zn and Cu mix and occupy the centers of symmetrical structure units which are coordinated to two ligands The measured bond lengths and angles of O-M-O vary with the ratio of metal species over the entire series of the synthesized complexes The chemistry of the as-synthesized compounds has been characterized using infrared spectroscopy mass spectroscopy energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy analysis and the morphology of the products has been characterized using scanning electron microscopy The thermal decomposition of the Z0 7C0 3AA composites measured by thermo gravimetric analysis suggests that these complexes are volatile The thermal characteristics of these complexes make them attractive precursors for metal organic chemical vapor deposition Chapter 3 summarizes the doping process Cu doped ZnO by these precursors series (Cu 1-10 at%) Bis (acetylacetonato κ-O O') [zinc (II)/copper (II)] Hybrid Organic-inorganic Complexes The species that we were able to control the amount of the percentage of this reaction indicate that is not a simple formation but possibly proceeds control amount of hybrid precursors to controllable of Cu(I) and Cu(II) in doping process The second class that we attempted to examine as zinc/copper precursors for XPS and PL chemical were the Cu(I) Cu(II) controllable we studied the Photocatalyst of a series of these precursors (Cu 1-10 at%) Finally in Chapter 4 we came up to the conclusion of this research In this research we synthesized and Characterized a series of Bis (acetylacetonato κ-O O') [zinc/copper] Hybrid Organic-inorganic Complexes as Solid Metal Organic Precursor we provided an overview of interpenetration involved optical and magnetic properties in metal organic precursors (MOPs) or coordination organic materials Successful approaches for controlling the interpenetration in MOPs also have been introduced and summarized The formation of a complete solid solution between acetylacetonate (acac) complexes of zinc nitrate and copper nitrate [(Zn1_xCux)(acac)2] has been investigated through the co-synthesis method Well crystallized single crystal diffraction SCD EDX XPS analysis was fulfilled for each nominal value of x confirming The UV/Blue and green (near-white) emissions were found in photoluminescence spectra indicating the possibility to use the Cu doped ZnO Nano rods structures on ZnO substrate Optical studies of the nanostructured copper doped zinc oxides showed the decrease in band gap with increasing content of the doping agent copper The photocurrent action spectra illustrated that the enhanced photo activity of the Cu-doped ZnO Nano rods was mainly due to the improved visible photon harvesting achieved by Cu doping These results may facilitate the use of transition metal ion-doped ZnO in other photo conversion applications such as ZnO based dye-sensitized solar cells and magnetism-assisted photocatalytic systems It is revealed from PL studies that the band-edge/UV-vis emission decreases whereas the visible emission is found to increase with increase of the doping concentration The decrease in the band-edge emission can be attributed to the substitution of Zn by Cu ions in the ZnO lattice Finally we synthesized Cu doped ZnO nanostrucyures by these series Hybrid Organic-inorganic precursors We were able to control the amount of the percentage of this reaction indication that is not a simple formation but possibly proceeds control amount of hybrid precursors to controllable of Cu(I) and Cu(II) in doping process the crystal structure was characterized by X-ray diffraction (XRD) scanning electron microscopy (SEM) energy-dispersive spectroscopy (EDX) transmission electron microscopy (TEM) UV–vis spectrum photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS) are used to characterize the material properties

Date of Award	2017 Jun 27
Original language	English
Supervisor	Chuan-Pu Liu (Supervisor)