Abstract
A simple method for the synthesis of ZnO nanofilms composed of vertical array of quasi-1D ZnO nanostructures (quasi-NRs) on the surface was demonstrated via a 1D crystal growth of the attached nanoseeds under a rapid hydrolysis process of zinc salts in the presence of ammonia at room temperature. In a typical procedure, by simply controlling the concentration of zinc acetate and ammonia in the reaction, a high density of vertically oriented nanorod-like morphology could be successfully obtained in a relatively short growth period (approximately 4 to 5 min) and at a room-temperature process. The average diameter and the length of the nanostructures are approximately 30 and 110 nm, respectively. The as-prepared quasi-NRs products were pure ZnO phase in nature without the presence of any zinc complexes as confirmed by the XRD characterisation. Room-temperature optical absorption spectroscopy exhibits the presence of two separate excitonic characters inferring that the as-prepared ZnO quasi-NRs are high-crystallinity properties in nature. The mechanism of growth for the ZnO quasi-NRs will be proposed. Due to their simplicity, the method should become a potential alternative for a rapid and cost-effective preparation of high-quality ZnO quasi-NRs nanofilms for use in photovoltaic or photocatalytics applications.PACS: 81.07.Bc; 81.16.-c; 81.07.Gf.
Highlights
ZnO nanocrystals, such as nanorods, nanowires and nanoparticles, have been receiving a growing research attention in the last few decades due to their unique electrical and optical properties [1,2,3,4,5,6]
Further analysis on the surface morphology found interestingly that the quasi-NRs density relatively increased with the increasing of ammonia concentration
Besides modifying the diameter and the length, the variation of ammonia significantly alters the overall nanorod density on the surface; namely it improves with the increasing of ammonia concentration
Summary
ZnO nanocrystals, such as nanorods, nanowires and nanoparticles, have been receiving a growing research attention in the last few decades due to their unique electrical and optical properties [1,2,3,4,5,6]. A hydrothermal method seems to be the potential approach for a better synthetic control for a catalyst-free 1D ZnO growth on the substrate surface This technique realises the growth of vertically oriented ZnO nanorods on the surface from the nanoseeds under a lowtemperature hydrothermal process (approximately 60°C to 150°C) in an autoclave. We demonstrate an alternative method for preparing high-density, vertically oriented quasi-1D ZnO nanofilms on the surfaces via a 1D crystal growth of nanoseeds under a simple ambient-temperature hydrolysis process of zinc salt in the presence of ammonia with a relatively short growth period. The clear solution of zinc acetate immediately changed to a translucent bluish colour for the first 1 to 3 min of the process (inferring a rapid hydrolysis of zinc complexes in the growth solution) and disappeared, a reflection of complete olation process of zinc complexes on the nanoseeds surface This phenomenon was again obtained every time the ammonia was added into the solution. The optical property of ZnO quasi-NRs on FTO surface was characterised using a Perkin Elmer double-beam UV/VIS/NIR spectrophotometer model Lambda 900
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
