Effect of Substrates on Structural and Optical Properties of Tin Oxide (SnO₂) Nanostructures

Abstract

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.

Carbothermal synthesis of metal-functionalized nanostructures for energy and environmental applications

“…60 In this facile method, the morphology and properties of nanowires are mainly controlled by growth parameters such as temperature, thickness of the catalyst layer, rate of carrier gas ow, and distance between the source and the substrate. 61 Different types of nanostructures are obtained at different locations on an Au/ alumina substrate. ZnO/SnO 2 nanowires possess a comb-like branched structure in Fig.…”

Tin oxide based nanostructured materials: synthesis and potential applications

“…Then this vaporized material is condensed to form the desired nanostructure by controlling conditions like substrate amount, temperature, and pressure. [40][41][42][43][44] Researchers are working on various synthesis routes to prepare nanomaterials and nanocomposites for specific applications. For nanocomposite synthesis, factors such as the kinetic energy of the added dopant atom, source to substrate ratio, and metal coating thickness come into play.…”

“…Similarly, Choi 81 synthesized metal oxide nanowires for optoelectronics using a vapor-liquid-solid (VLS) growth mechanism. In addition, Johari et al 42 also showed the synthesis of SnO 2 nanowires via a vapor-liquid-solid (VLS) growth mechanism where the metal oxide is grown on Au/Si nanospheres to form a SnO 2 /Au/Si nanocomposite.…”

Recent insights into SnO2-based engineered nanoparticles for sustainable H2generation and remediation of pesticides

“…Thermal deposition occurs in a tube furnace, where powdered materials are vapor condensed at conditions such as temperature and pressure. [151][152][153] To form nanostructured materials, several steps are followed: (1) formation of evaporant at the source, (2) evaporant transport to the substrate, and (3) condensation onto the substrate to synthesize the desired NMs. 128 To customize the nanostructure, specific parameters are to be considered, such as kinetic energy, flow rate, and scattering of gas.…”