Effect of Fe Doping on Photocatalytic Dye-Degradation and Antibacterial Activity of SnO2 Nanoparticles

A simple hydrothermal method is utilized to synthesize iron-doped tin oxide nanoparticles (Fe-SnO2 NPs) at various doping concentrations. The structural characterization using XRD, Raman, and FTIR measurements confirmed the incorporation of Fe ions into the SnO2 lattice without any deviation in the tetragonal crystal system of SnO2 nanoparticles. SEM and HRTEM images show the spherical-shaped nanoparticles with agglomeration. The values of interplanar spacing ( d -value) calculated from the HRTEM lattice are consistent with the XRD results. Further, optical analysis revealed a red shift in the optical absorption band and a decrease in the band gap energy with an increase in Fe-dopant concentration. The decrease of PL emission peak intensity with Fe doping revealed the generation of singly charged oxygen vacancies. The H2O2-assisted photocatalytic degradation efficiency of Fe-SnO2 NPs investigated against crystal violet dye indicated an efficiency of 98% for 0.05 M Fe-SnO2 NPs within 30 minutes under visible light illumination. In addition, the effects of pH, scavengers, and reusability of the catalyst are tested. The antibacterial behavior of Fe-SnO2 NPs against Escherichia coli is examined by using the colony count method, and the inhibition rate was found to be 49, 65, 70, and 78% for pure, 0.01, 0.03, and 0.05 M Fe-SnO2 NPs, respectively

Studies on lipase enzyme production by indigenously isolated Bacillus Cereus (BAIT GCT 127002 ) and Bacillus Cereus (BAIT GCT 127001)

Microbial lipases holds a prominent place among biocatalysts that act on carboxylic ester bonds.  This present study involves about eight strains isolated form slaughter house waste water,Coimbatore producing lipase.Among those strains , two bacterial strains exhibiting high lipase production  were identified as  Bacillus Cereus (BAIT GCT 127002 ) and Bacillus Cereus (BAIT GCT 127001 ) by both biochemical analysis and 16S rRNA sequencing.  Initial studies were done for optimizing lipase production using many components such as time course,Carbon sources ,pH and innoculum volume which  revealed maximum lipase acitivity (43.37 U/ml) at 24 hours, using  palm oil , at pH 8 and innoculum volume of 1 ml by Bacillus Cereus (BAIT GCT 127002 ).Further the percentage  removal of oil from oil stained fabric was determined using partially purified lipase with or without detergents and the results indicated 20% ,30% removal with use of  crude lipase and commercial detergent respectively.Hence, lipase from Bacillus Cereus(BAIT GCT 127002 )   can be regarded as an ideal ingredient that can be used in the laundry detergents.Â&nbsp