Nanoscale Materials and their Applications — DU Physical Science courses pertaining to Chemistry Previous Year Question Papers

(b) Compare the advantages of nano-catalysts over traditional bulk catalysts. 5 (c) Discuss the application of nanomaterials as catalysts in the energy sector. 5 Materials and Their 1. (a) How are nanomaterials classified based on their dimensionality ? Explain with examples. 5 (b) Discuss the method of formation, properties and applications of carbon nanotubes. 5 (c) What do you understand by vacuum deposition ? Describe working of thermal evaporation using suitable diagram. 5 2. (a) Write short notes on. 5 (ii) Nano wires (b) Explain the quantum confinement effect in nanostructured materials and its consequences. 5 (c) Briefly describe how core-shell nanoparticles could be made using either vapour-phase or solution-based techniques. 5 3. (a) Differentiate between SEM and TEM methods of nanomaterial characterization. (b) Explain the effect of reducing particle size on the band gap of a semiconductor. 5 (c) Write short notes on. (i) Sol-Gel method for the synthesis. (ii) Bottom up and Top-down approach for nanomaterials. 4. (a) Give one method of preparation of silver nanoparticles. Explain the steps involved. 5 (b) Explain Hydrothermal method for the synthesis of nanomaterials. 5 (c) Give full form of the following. 5 5. (a) Discuss the application of nanowires in solar cells, LEDs, and transistors. 5 (b) What are the main Advantage of using nanocomposites as catalysts over conventional homogeneous catalysts. 5 (c) Discuss on the sol-gel method for the synthesis of nanoparticles. Explain how grain size can be controlled in sol-gel process. 5 6. (a) Explain the significance of the surface-to-volume ratio in nanoparticles. Discuss how this ratio affects the physical and chemical properties of the nanoparticles. 5