From UPSC perspective, the following things are important :
Prelims level : Nanomaterials, Semiconductors
Mains level : Applications of nanomaterials
Researchers are exploring ways to develop plasmonic semiconductor nanomaterials for removal of toxic organic compounds from water by harvesting solar light.
Nanotechnology is a pathbreaking technology which can create many new materials and devices with a wide range of applications, such as in nanomedicine, nanoelectronics etc. PSN is one such application. Topics like PSN are most likely to be asked in the competitive examinations.
Plasmonic Semiconductor Nanomaterials
- PSN are metal-like materials with free electrons on the surface that oscillate collectively when hit by light.
- It uses solar light to increase the photocatalytic efficiency to degrade pollutants as well as generate renewable Hydrogen.
- These materials can easily adsorb toxic ions like arsenic and fluoride, which are often found in water in North East India and convert it to its not toxic forms when they are exposed to sunlight.
- PSN can be used for hydrogen energy generation, a process which has shown high photon to hydrogen conversion efficiency under visible and near infra-red light.
What are Semiconductors?
- Semiconductors are materials which have a conductivity between conductors (generally metals) and nonconductors or insulators (such as most ceramics).
- Its resistance falls as its temperature rises; metals are the opposite.
- They can be pure elements, such as silicon or germanium, or compounds such as gallium arsenide or cadmium selenide.
- Nanomaterials are materials of which a single unit small-sized (in at least one dimension) between 1 and 100 nm (the usual definition of nanoscale).
- Materials with structure at the nanoscale often have unique optical, electronic, or mechanical properties.
- They are created from the gas phase by producing a vapour of the product material using chemical or physical means.
- Examples of nanomaterials include carbon nanotube, nanoparticles, metal rubber, quantum dots, nanopores and many more.