| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2014) | |
| Nanomaterials | Wednesday Sessions |
| Session NM-WeP |
| Session: | Nanomaterials Poster Session |
| Presenter: | BG Ganga, Indian Institute of Technology Madras, India |
| Authors: | B.G. Ganga, Indian Institute of Technology Madras, India P. Santhosh, Indian Institute of Technology Madras, India |
| Correspondent: | Click to Email |
CuO is a versatile p-type transition metal oxide semiconductor with a narrow band gap in the region 1.2-1.8 eV [1]. It is a naturally abundant, nontoxic and stable material and is commonly used as a component material in a wide range of applications such as gas sensing, catalysis and energy storage and conversion [2-4]. Three dimensional ellipsoidal shaped CuO nanostructures and two dimensional nanosheets have been successfully synthesized using surfactant free simple solution phase method. Synthesis of CuO nanostructures was followed by structural, morphological characterization using X-ray diffraction, Scanning Electron Microscopy and Transmission Electron Microscopy. We have demonstrated that morphology and dimensionality of nanostructures can be controlled by changing the initial reactant concentrations. It is observed that ordered aggregation and growth of smaller CuO subunits generates an ellipsoidal shaped morphology at lower reactant concentration, while at higher reactant concentration, sheet like structures are generated. Self-assembled structures provide an opportunity to investigate the formation mechanism and aggregation based growth of nano subunits as fundamental building blocks. This bottom-up method offers facile synthesis of nanostructures of controlled morphology and functionality. We have also observed a change in morphology as the nanostructures were thermally annealed. A morphological transformation from rod-like to plate-like structure was observed as the flake-like nanostructures were annealed at 4000C and 6000C respectively. The formation mechanism that plays behind the generation of different CuO nanostructures is explored. Optical properties are investigated using UV-Vis spectroscopy and Raman spectroscopy. We found that morphology of the nanostructure strongly reflect on the optical properties as band gap widening and the change in the position and width of Raman modes.
References
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