Past and Present Research Systems of Green Chemistry

Biography

Biography: Arik Kar

Abstract

SnO2 is a significant metal-oxide, n-type wide band gap (3.6 eV at 300K) semiconductor. Due to its outstanding electrical, optical and electrochemical properties, SnO2 offers a broad range of applications in solar cells, catalytic support materials, transparent electrodes and solid state chemical sensors. However, in terms of several of these applications, pure SnO2 nanocrystals show a few classical drawbacks, mainly due to their large surface-to-volume ratio. Two standard strategies to advance the application-based performance of SnO2 are its mixing and coating with another semiconductor material. Nowadays, nanocomposite and heterostructure materials comprised of two semiconductors of different band gap are proving of immense interest to researchers due to their superior electrical, optical, and electrochemical properties. In my presentation, I will discuss the fabrication, structures and application-based properties of SnO2-PbS nanocomposite and heterostructure materials. First I will describe some innovative solution and microwave synthetic techniques for the preparation of pure SnO2 nanoparticles/nanospheres, pure PbS nanocubes, SnO2-PbS nanocomposites and heterostructures. The structures are confirmed by X-ray diffraction (XRD)/Reitveld study, Raman spectroscopy and transmission electron microscopy (TEM) analysis. Elemental mapping and line scan EDX analysis successfully demonstrate the effective PbS deposition on SnO2 nanospheres as well as the mixing of SnO2 and PbS to form nanocomposites. I will present a model to explain different relaxation processes in SnO2-PbS nanocomposite and heterostructure which helps to understand how the two semiconductors interact. Lastly, I will discuss some application-based properties of as-synthesized nanocomposite and heterostructure materials which are found to be significantly improved relative to pure SnO2 or PbS.