Kuntal Chatterjee

Photocatalytic and antibacterial activity of cadmium sulphide/zinc oxide nanocomposite with varied morphology

Nanocomposites with multifunctional application prospects have already dragged accelerating interests of materials scientists. Here we present CdS/ZnO nanocomposites with different morphology engineering the precursor molar ratio in a facile wet chemical synthesis route. The materials were structurally and morphologically characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray analysis (EDX) and high-resolution transmission electron microscopy (HRTEM). The growth mechanism of the composite structure with varying molar ratio is delineated with oriented attachment self assemble techniques. Photocatalytic activity of CdS/ZnO nanocomposites with varying morphology were explored for the degradation of rhodamine B (RhB) dye in presence of visible light irradiation and the results reveal that the best catalytic performance arises in CdS/ZnO composite with 1: 1 ratio. The antibacterial efficiency of all nanocomposites were investigated on Escherichia coli, Staphylococcus aureus and Klebsiella pneumonia without light irradiation. Antibacterial activity of CdS/ZnO nanocomposites were studied using the bacteriological test-well diffusion agar method and results showed significant antibacterial activity in CdS/ZnO composite with 1:3 ratio. Overall, CdS/ZnO nanocomposites excel in different potential applications, such as visible light photocatalysis and antimicrobial activity with their tuneable structure.

Morphology dependent magnetic properties of α-Fe2O3 nanostructures

Well crystalline α-Fe2O3 nanomaterials with a wide range of morphology variation have been successfully synthesized by solvothermal route. The synthesized products have been characterized for structural and morphological details by employing x-ray diffraction patterns, transmission electron microscopy, field emission scanning electron microscopy and energy dispersive x-ray spectroscopy. Various unique shapes of α-Fe2O3 nanocrystal have been modelled on the basis of their growth evolution. The effect of morphology of α-Fe2O3 nanocrystals on their magnetic behaviour has been studied by investigating temperature and field dependence of magnetization. The results are analyzed considering all the possible surface anisotropy and lattice strain evolved due to their surface structure. This comprehensive study of morphology dependent magnetic behaviour of α-Fe2O3 nanomaterials offers a better opportunity to tune the materials in the desired technological applications.

MoS2 embedded TiO2 nanoparticles for concurrent role of adsorption and photocatalysis

In this work, MoS2 embedded TiO2 nanoparticles, synthesized through hydrothermal process, was successfully employed to remove organic pollutant dye like methylene blue(MB) through adsorption and as well as through photocatalysis under visible light irradiation. The system was characterized by structural and morphological study. The adsorption and photocatalytic study of MB were evaluated with different concentrations of dye in aqueous solution. This work brings the MoS2-TiO2 nanostructure as excellent adsorbent as well as efficient photocatalyst materials which can be used for organic dye removal towards waste-water treatment.In this work, MoS2 embedded TiO2 nanoparticles, synthesized through hydrothermal process, was successfully employed to remove organic pollutant dye like methylene blue(MB) through adsorption and as well as through photocatalysis under visible light irradiation. The system was characterized by structural and morphological study. The adsorption and photocatalytic study of MB were evaluated with different concentrations of dye in aqueous solution. This work brings the MoS2-TiO2 nanostructure as excellent adsorbent as well as efficient photocatalyst materials which can be used for organic dye removal towards waste-water treatment.

MoS2-Carbon Nanotube Porous 3 D Network for Enhanced Oxygen Reduction Reaction

Future generation power requirement triggers the increasing search for electrocatalysts towards oxygen reduction, which is the pivotal part to enhance the activity of metal-air batteries and fuel cells. The present article reports a novel 3 D composite structure weaving 1 D carbon nanotubes (CNT) and 2 D MoS2 nanosheets. The MoS2 -CNT composite exhibits excellent electrocatalytic activity for the oxygen reduction reaction (ORR) in alkaline environment. Measurements show better methanol immunity and higher durability than Pt/C, which is considered the state-of-the-art catalyst for ORR. Experimental results suggest that the hybridization of 1 D functionalized multiwalled CNTs (MWCNTs) and exfoliated 2 D MoS2 nanosheet results significant synergistic effect, which greatly promotes the ORR activity. This work presents a new avenue to rationally design a 3 D porous composite out of 1 D and 2 D interlaced components and demonstrate appreciable electrochemical performance of the materials towards ORR activity for fuel cells as well as metal-air batteries.