MICROBIAL BIOSYNTHESIS OF CADMIUM SULFIDE (CDS) NANOPARTICLES AND THEIR CHARACTERIZATION

Swati Tandon and Siddharth Vats*

ABSTRACT

Green synthesis of the Cadmium Sulfide nanoparticles with novel, clean and biological transformation with unique properties, finding potential application in emerging field of nano-photonics & nanoelectronics has been carried out. The average particle size of cadmium sulphide (CdS) nanoparticles prepared by biological routes using immobilized microbes like Pseudomonas aeruginos, Bacillus lichenisformis, Escherichia coli, Fusarium oxysporum & Aspergillus terrus, was 17.86, 17.00, 17.86, 18.73 and 13.21 nm respectively. Variety of visual analysis techniques were performed like UV-vis optical absorption photoluminescence spectra and Atomic Force Microscopy (AFM) for structural characterization of the nanoparticles. The optical band gap of these materials has been determined in order to establish a relationship between energy band gap of bulk and nano materials. Change in the colour of Cadmium chloride and sodium sulfide solution indicates the synthesis of cadmium sulfide nanoparticle, the resultant shows the absorbance at characteristics peak for each CdS nanoparticle at 465, 459, 465, 468 and 428 nm respectively. Band of gap obtained for the microbes confirms the success full biosynthesis of nano particles with value for Pseudomonas aeruginosa (2.66eV), Bacillus lichenisformis (2.71eV), Escherichia coli (2.66eV), Fusarium oxysporum (2.64eV) & for Aspergillus terrus (2.90eV). The randomly selected nanoparticles obtained from microbes (Pseudomonas Aeruginosa and Aspergillus terrus) were subjected to 3D visualization and characterization by the use of AFM. Photo catalytic dye-degradation was also performed to all the biologically synthesised cadmium sulphide nanoparticles.

Keywords: Nanoparticle’s, Cadmium Sulfide, U.V, Band Gap, Photo Catalytic & AFM.