Hydrothermal growth of nanostructured Zinc oxide
Abstract
Hydrothermal method was used to prepare ZnO nanostructure .This study haven’t used any catalyst or buffer layer before the reaction. The process has taken place inside Teflon lined stainless steel autoclave with volume 100 ml (homemade). ZnO nanotubes, lettuce leaf nanostructure, and nanosticks were successfully synthesized using ZnO nanoparticles (20-30 nanometers) and NaOH (concentrations 6M) which was the starting materials for the chemical reaction under stirring. The suspension was transferred into a Teflon lined sealed stainless steel autoclave and kept at 70 0C for 24, 48, and 72 hour. The influence of the time reaction of synthesis process on the morphology, the crystallinity and structural properties are studied by X-ray diffraction and field emission scanning electron microscope (FE-SEM), the experimental pattern of the films show that diffraction peaks can be assigned to the Wurtzite hexagonal-shaped ZnO as shown in the FE-SEM pictures, also the morphology of the films studied by atomic force microscope (AFM) shows that the prepared thick films have high roughness specially for the powder prepared 48 h .
Keywords
Download Options
Introduction
Zinc oxide(ZnO) has extensive commercial use during the past 100 years .The low size (Nano, micro)materials have interesting attention due to their size dependent properties and wide range of applications in different fields such as industry, health and environment[1-5] with special important applications in optoelectronics, nano/microelectronics, sensors, transducers, and biomedicine . In the group of II-VI compound semiconductors, ZnO has received great attention due to its remarkable combination of physical and optical properties. Its wide band gap (3.37 eV) at room temperature, high excitation binding energy (60 meV) [6,7], Nanowires and carbon nanotubes and other nano structures made from different row materials (organic/inorganic).Many preparation methods are now available and give research domain for analyzing and understanding the one-dimensional nanostructures and their future applications[8,9].Extensive efforts are currently devoted to the controlled synthesis and characterization of ZnO nanostructures. Several different methods for the fabrication of ZnO nanostructures (nanorods, nanotubes, nanowire, nanobelts) and arrays have been reported, including hydrothermal synthesis [10-13],Vapour–liquid–solid (VLS), vapour–solid (VS) [14] processes, metal–organic chemical vapor deposition (MOCVD) [15], chemical vapor deposition [16], and solution-liquid-solid growth in organic solvents [17-19].Recently, one-dimensional (1D) zinc oxide materials and differently shaped ZnO nanocrystals have attracted considerable attention due to their unique properties that strongly depend on their size and morphologies and their possible use as building blocks in near-future nanodevices [13]. 2D- and 3D-shaped ZnO nanocrystals will play a significant role as the novel functional units of electronic, electromechanical and optoelectronic devices [20-22], and nanosensors [11, 12 and 23].Novel synthesis routes of ZnO nano rods for solar cells and chemical sensing applications are currently being developed. The latest research efforts are directed towards obtaining alternative, lightweight, flexible nanodevices [15, 24] .the reference[25]was reviewed summarize the condition leading to the growth of different ZnO nanostructures using hydrothermal technique.
Conclusion
ZnO nano structures synthesis with hydrothermal technique is simple and efficient and it is receiving a lot of attention of late. The nanostructures are opening new applications such as nanodevices. The results presented in this article demonstrated that the effected of the parameters deal with that growth temperature. ZnO lettuce leaf can be grown in solution and changed to nanotube shape by increasing the growth reacting time during the growth process.