CONTENTS INTRODUCTION EXPERIMENTAL

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1 CONTENTS PREFACE 1. INTRODUCTION 1.1 Metal Oxides Review of the methods and applications of metal/mixed metal oxides of transition metals Catalyst Photo catalyst Sensors Superconductors Adsorbents Ceramics Fuels REFERENCES EXPERIMENTAL 2.1 Materials used Equipment used 2.3 Calibration of ph meter Synthesis of nanosized metal oxides CHACTERIZATION TECHNIQE Powder X-Ray Diffraction Magnetic Measurement TGA/DTA SEM TEM 116 iv

2 CHAPTER 3: SYNTHESIS AND CHARACTERISATION OF NANOSIZED METAL OXIDES (RESULTS AND DISCUSSION 3.1 A simple and effective method of the synthesis of Fe 2 O 3 nanoparticles A simple and effective method of the synthesis of nanosized CuO particles A simple and effective method of the synthesis of nanosized ZnO particles A simple and effective method of the synthesis of nanosized NiO particles References 155 CHAPTER4: SYNTHESIS AND CHARACTERISATION OF NANOSIZED FERRITES (RESULTS AND DISCUSSION 4.1 A simple and effective method of the synthesis of nanosized ZnFe 2 O 4 particles A simple and effective method of the synthesis of single phase nanosized NiFe 2 O 4 particles A simple and effective method of the synthesis of nanosized CuFe 2 O 4 particles References 197 CHAPTER5: SYNTHESIS AND CHARACTERISATION OF NANOSIZED MIXED FERRITES (RESULTS AND DISCUSSION 5.1 A simple and effective method of the synthesis of nanosized Ni 0.5 Zn 0.5 Fe 2 O 4 particles A simple and effective method of the synthesis of nanosized Ni 0.5 Cu 0.5 Fe 2 O 4 particles A simple and effective method of the synthesis of nanosized Cu0.5Zn0.5Fe 2 O 4 particles References 233 CHAPTER6 CONCLUSIONS LIST OF PUBLICATIONS 244 v

3 LIST OF ABBREVIATIONS DTA Differential Thermal Analysis g Gram h Hours mg Milligram ml Milliliter MMO Mixed Metal Oxide PXRD Powder X-Ray Diffraction SEM Scanning Electron Microscopy TEM Transmission Electron Microscopy TGA Thermo gravimetric Analysis 0 C Degree Celsius vi

4 PREFACE This thesis describes the experimental studies carried out by the candidate on Synthesis and Characterization of some nanosized metal/mixwd metal oxides of some transition metals Chapter 1 deals with the importance for the synthesis of nanosized metal/mixed metal oxides of various metals. It describes the literature on the various types applicatios of metal/mixed metal oxides that were employed for the synthesis of mixed metal oxides in particular. The various applications of metal/mixed metal oxides as catalyst, photocatalyst, sensors, superconductors, adsorbents, ceramics and fuels have been discussed briefly. [1-422] Chapter 2 gives details about the various materials, preparation method and basis principles of various analytical techniques such as powder X-Ray Diffraction, Thermogravimetric Analysis and Differential Thermal Analysis (TGA and DTA), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM),Surface area measurements that have been employed for the current investigation of metal/ mixed metal oxides. In general most of nanosized metal/mixed metal oxides have been synthesized at 70 0 C and then calcined at higher temperature ranging from 500 and C. The method used for synthesis of metal / mixed metal oxides is simple, cheap, easy, less time consuming and most reliable. Chapter 3 describes the results and discussion of various nanosized metal oxides of Cu, Zn, Fe and Ni. Characterization of metal oxides by using various analytical techniques such as powderd X-Ray Diffraction, Thermogravimetric Analysis and Differential Thermal Analysis (TGA and DTA), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and surface area measurements have been employed for the current investigation of metal oxides. In general most of metal /mixed metal oxides have been synthesized at 70 0 C as compared to the temperatures required for the solid state method of preparation. The method used for synthesis of metal oxides is simple, cheap, easy, less time consuming and most reliable. All metal oxides of transition metals were nanosized and found in good agreement of theoretical value of nanosized metal oxides. Chapter 4 describes the synthesis and characterization of nanosized scale of Nickel ferrite,copper Ferrite and Zinc Ferrite. ZnFe 2 O 4 nanoparticles with spinel structure are synthesized successfully by aqueous precipitation method by using ammonia as precipitating agent. From TEM study it is found that particles are having average size of nm. Magnetic measurements show that ZnFe 2 O 4 is super paramagnetic in nature having saturation magnetization (Ms) value 50 emu/g. This method is advantageous over existing methods of vii

5 synthesis of nanoparticles because other methods require specialized instrumentation, highly skilled labour, expensive materials and methods. Therefore, the proposed precipitation method is very promising, easy and cheap and may have extensive applications. NiFe 2 O 4 nanoparticles with cubic structure have been synthesized successfully by aqueous precipitation method. TEM study show very fine nanoparticles of diameter nm with average size of 20nm. VSM studies show ferromagnetic behavior of synthesized nanoparticles.xrd pattern of the sample shows nano crystalline nature of the sample. It has been observed that the material prepared is having lattice constant of 8.398A 0. The average particle size of synthesized ferrite were observed to the 20 nm which is well supported by SEM/TEM micrographs. Magnetic measurements show that CuFe 2 O 4 is super paramagnetic in nature having saturation magnetization (Ms) value 50 emu/g. The notable advantages are high yield of product less expensive, shorter reaction times, mild reaction, conditions and easy workup.this method is advantageous over existing methods of synthesis of nanoparticles because other methods require specialized instrumentation, highly skilled labour, expensive materials and methods. Therefore, the proposed precipitation method is very promising, easy and cheap and may have extensive applications. Chapter 5 describes the synthesis and characterization of nanosized scale of Nickel ferrite,copper Ferrite and Zinc Ferrite. Ni 0.5 Zn 0.5 Fe 2 O 4 nanoparticles with cubic spinel structure are synthesized successfully by aqueous precipitation method. From TEM study it is found that particles are having size of nm with average size. Magnetic measurements show that Ni 0.5 Zn 0.5 Fe 2 O 4 is super paramagnetic in nature having saturation magnetization (Ms) value 29 emu/g. This method is advantageous over existing methods of synthesis of nanoparticles because other methods require specialized instrumentation, highly skilled labour, expensive materials and methods. Ni 05 Cu 0.5 Fe 2 O 4 nanoparticle with cubic spinel structure have been synthesized successfully by aqueous precipitation method. From SEM/TEM studies it is found that particles have average size 18-34nm. Magnetic measurements shows that Ni 05 Cu 0.5 Fe 2 O 4 is super paramagnetic in nature having saturation magnetization (MS) value 52 emu/g. Cu 05 Zn 0.5 Fe 2 O 4 nanoparticle with cubic spinel structure are synthesized successfully by aqueous precipitation method. From TEM studies it is found that particles have average size 18-68nm. Magnetic measurements shows that Cu 05 Zn 0.5 Fe 2 O 4 is super paramagnetic in nature having saturation magnetization (MS) value 51 emu/g. This method is beneficial over the existing methods of synthesis of nano particles because other methods require expensive materials, highly skilled labour and specialized instrumentation. Therefore, viii

6 the proposed precipitation method is cheaper, easier, very promising and may have extensive applications. Chapter6 describes the conclusions of the work done. ix

7 LIST OF TABLES Table Description Page No. 2.1 List of various chemicals used in experimental work X-Ray diffraction data for iron oxide Observation on magnetic susceptibilities of synthesized nickel oxide Observations of weight loss for iron oxide at corresponding temperature range Particle size of synthesized iron oxide at different scales Magnetic susceptibility data of iron oxide X-Ray diffraction data for copper oxide Observation on magnetic susceptibilities of synthesized copper oxide Observations of weight loss for copper oxide at corresponding temperature range Particle size of synthesized copper oxide at different scales X-Ray diffraction data for zinc oxide Observations of weight loss for zinc oxide at corresponding temperature range Particle size of synthesized zinc oxide at different scales X-Ray diffraction data for nickel oxide Observation on magnetic susceptibilities of synthesized nickel oxide Observations of weight loss for nickel oxide at corresponding temperature range X-Ray diffraction data for zinc ferrite Reported value of saturation magnetization in literature Observations of weight loss for zinc ferrite at corresponding temperature range Particle size of synthesized zinc ferrite at different scales X-Ray diffraction data for nickel ferrite Size and magnetic parameters for synthesized nickel ferrite Size and magnetic parameters for synthesized nickel ferrite Observations of weight loss for nickel ferrite at corresponding temperature range Particle size of synthesized nickel ferrite at different scales X-Ray diffraction data for copper ferrite Observations of weight loss for copper ferrite at corresponding temperature range Particle size of synthesized copper ferrite at different scales X-Ray diffraction data for nickel zinc ferrite Reported value of saturation magnetization in literature Observations of weight loss for nickel zinc ferrite at corresponding temperature 216 range 5.4 Particle size of synthesized nickel zinc ferrite at different scales X-Ray diffraction data for nickel copper ferrite Observations of weight loss for nickel copper ferrite at corresponding temperature 218 range 5.7 Particle size of synthesized nickel copper ferrite at different scales X-Ray diffraction data for copper Zinc ferrite Observations of weight loss for copper zinc ferrite at corresponding temperature 221 range 5.10 Particle size of synthesized copper zinc ferrite at different scales 221 x

8 LIST OF FIGURES Figure No. Description Page No. 3.1 XRD spectra of synthesized iron oxide (a) Morin transition curve for synthesized iron oxide nanoparticles. 140 (b) VSM studies of synthesized iron oxide. 3.3 TGA/DTA curve of iron oxide heated at 70 o C SEM images of iron oxide particles TEM images of iron oxide particles XRD spectra of synthesized copper oxide VSM images of copper oxide particles TGA-DTA images of copper oxide particles SEM images of copper oxide particles TEM images of copper oxide particles X-ray diffraction patterns of calcined zinc oxide Manetic measurements of synthesized ZnO TGA-DTA graph of zinc oxide SEM Micrographs of zinc oxide TEM micrograph of zinc oxide under high magnification (Scale bar is 20 nanometer XRD spectra of synthesized nickel oxide Manetic measurements of synthesized ZnO TGA/DTA curve of nickel oxide heated at 70 o C SEM micrographs of nickel Oxide particles TEM micrographs of nickel oxide particles XRD spectra of Zinc Ferrite Magnetic measurement of synthesized Zinc ferrite particles TGA-DTA of zinc ferrite particles SEM images of zinc ferrite TEM images of zinc ferrite nanoparticles XRD spectra of nickel ferrite Magnetic measurements of nickel ferrite nanoparticles TGA-DTA of nickel ferrite particles SEM images of nickel ferrite TEM images of nickel ferrite nanoparticles XRD spectra of copper ferrite Magnetic measurement of synthesized copper ferrite particles TGA-DTA of copper ferrite particles SEM images of copper ferrite particles TEM images of copper ferrite particles XRD spectra of Ni 05 Zn 0.5 Fe 2 O Magnetic measurement of synthesized Ni 05 Zn 0.5 Fe 2 O 4 Particles TGA-DTA of Ni 05 Zn 0.5 Fe 2 O 4 Particles SEM micrographs of Ni 05 Zn 0.5 Fe 2 O 4 Particles TEM images of Ni 05 Zn 0.5 Fe 2 O 4 particles X-Ray diffraction spectra of Ni 05 Cu 0.5 Fe 2 O 4 Particles Magnetic measurement of synthesized Ni 05 Cu 0.5 Fe 2 O 4 Particles TGA-DTA of Ni 05 Cu 0.5 Fe 2 O 4 Particles SEM micrographs of Ni 05 Cu 0.5 Fe 2 O 4 Particles TEM micrographs of Ni 05 Cu 0.5 Fe 2 O 4 Particles X-Ray diffraction spectra of Cu 05 Zn 0.5 Fe 2 O 4 Particles Magnetic measurement of synthesized Cu 05 Zn 0.5 Fe 2 O 4 particles TGA-DTA of Cu 05 Zn 0.5 Fe 2 O 4 Particles SEM micrograph of Cu 05 Zn 0.5 Fe 2 O 4 Particles TEM micrographs Cu 05 Zn 0.5 Fe 2 O 4 particles 232 xi

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