One-dimensional wire shaped tin oxide (SnO 2 ) nanostructures have been synthesized by thermal evaporation method. The growth of SnO 2 nanostructure was carried out on gold catalyst layer coated silicon substrate. X-ray diffraction (XRD) results reveals that synthesized SnO 2 nanowires have polycrystalline nature with tetragonal rutile structure. SEM, TEM and EDX observation concludes that the uniform SnO 2 nanowires (diameter ~ 40 nm and length ~ 50 μm) grow with vapor-liquid-solid (VLS) mechanism. I-V characteristics of single SnO 2 nanowire show semiconducting behaviour. Due to structural and electrical properties of SnO 2 nanowire, these nanowires would be a promising candidate for gas sensing applications.
We report on controlling the morphology of tin oxide (SnO2) nanostructures and the study of the effect of surface morphology on structural and optical properties of SnO2 nanostuctures. In present work, Tin oxide (SnO2) nanostructures such as nanowires and nanorods have been grown by thermal evaporation of SnO2 powder. To demonstrate the effect of different substrates on the morphology of grown SnO2 nanostructures, the thermal evaporation of SnO2 powder was carried out on Si and gold catalyzed Si (Au/Si) substrates. The scanning-electron-microscopic analysis shows the growth of SnO2 nanowires on Au/Si substrate and growth of SnO2 nanorods on Si substrate. The scanning-and transmission-electron-microscopic analysis shows that the diameter of SnO2 nanowires and nanorods are about 70 nm and 95 nm respectively and their length is about 80 microm and 30 microm respectively. The vapor-liquid-solid (VLS) growth of SnO2 nanowires and vapor-solid (VS) growth of SnO2 nanorods is also confirmed with the help of TEM and EDX spectra. The synthesized SnO2 nanowires show tetragonal rutile structure of SnO2, whereas SnO2 nanorods show tetragonal rutile as well as cassiterite structure of SnO2. UV-Vis absorption spectra showed the optical band gaps of 4.1 eV and 3.8 eV for the SnO2 nanowires and the nanorods, respectively. The SnO2 nanowires and nanorods show photoluminescence with broad emission peaks centred at around 600 nm and 580 nm respectively. Raman spectra of SnO2 nanowires shows three Raman shifts (478, 632, 773 cm(-1)) corresponding to Eg, A1g and B2g vibration modes, whereas in Raman spectra of SnO2 nanorods, A1g peak is dramatically reduced and the B2g mode is totally quenched.
In present work, pure and copper (Cu) doped SnO2 nanowires have been synthesized by thermal evaporation process at ambient pressure. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicated the growth of wire-like pure and Cu-doped SnO2 nanostructures with their length of about 50 microm and 80 microm whereas transverse dimension of about 50-80 nm and 20-50 nm, respectively. The HRTEM and SAED pattern reveals the growth of single crystalline Cu-doped SnO2 nanowire. The EDX confirms that Cu has been doped in the SnO2 nanowires and atomic fraction of Cu in nanowires is about 2.5 at% when concentration of CuO in starting source powder is 50 wt%. X-ray diffraction showed that Cu gets incorporated into the SnO2 lattice and also confirms their tetragonal rutile structure. For comparative study of gas sensing properties of pure and Cu-doped SnO2 nanowire, isolated single nanowire based sensors have been fabricated for detection of ethanol gas. The doping of Cu was found to enhance the ethanol sensitivity of SnO2 nanowire based sensors and the sensor response improves with increase in ethanol concentration. This sensing behaviour offers a suitable application of the Cu-doped SnO2 nanowire sensor for detection of ethanol gas.
One‐dimensional nanostructures of Tin oxide (SnO2) have been synthesized by thermal evaporation method with and with out a catalyst on silicon substrate. The nanostructure growth was carried out by using a mixture of SnO2 and graphite powders at a temperature of 1050C in nitrogen (N2) ambience. The synthesized SnO2 nanostructures show polycrystalline nature with tetragonal rutile structure. SEM investigation reveals wire‐like and rod‐shaped nanostructures on silicon substrate, with and without the gold catalyst layer respectively. EDX and TEM observation concludes that the uniform SnO2 nanowires (diameter ~ 25 nm and length ~ 50 μm) grow with vapor‐liquid‐solid (VLS) mechanism whereas, the SnO2 nanorods with varying diameter grow with vapor‐solid (VS) mechanism. UV‐ Vis spectra estimates that the optical band gaps of the SnO2 nanowires and nanorods were 3.92 eV and 3.67 eV respectively. As synthesized single SnO2 nanowire based gas sensor exhibit relatively good performance to ethanol gas. This sensing behaviour offers a suitable application of the SnO2 nanowire sensor for detection of ethanol gas
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.