In the present work, zinc oxide (ZnO) and silver (Ag) doped ZnO nanostructures are synthesized using a hydrothermal method. Structural quality of the products is attested using X-ray diffraction, which confirms the hexagonal wurtzite structure of pure ZnO and Ag-doped ZnO nanostructures. XRD further confirms the crystallite orientation along the c-axis, (101) plane. The field emission scanning electron microscope study reveals the change in shape of the synthesized ZnO particles from hexagonal nanoparticles to needle-shaped nanostructures for 3 wt% Ag-doped ZnO. The optical band gaps and lattice strain of nanostructures is increased significantly with the increase of doping concentration of Ag in ZnO nanostructure. The antimicrobial activity of synthesized nanostructures has been evaluated against the gram-positive human pathogenic bacteria, Staphylococcus aureus via an agarose gel diffusion test. The maximum value of zone of inhibition (22 mm) is achieved for 3 wt% Ag-doped ZnO nanostructure and it clearly demonstrates the remarkable antibacterial activity.

The different dyes in industries and microbial pathogenic issues have raised serious concerns in water bodies about the environment and human health. Efficiently treatment of contaminated water is a major...

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The current study unravels the structural, optical band gap and magnetic characteristics of rare-earth (RE) gadolinium (Gd) substituted CoGdxFe2-xO4 (x= 0.00 - 0.10, in the interval of 0.02) nanocrystallites synthesized by the sol-gel self-ignition route. The XRD analysis and Rietveld refinement confirmed the existence of a single cubic phase with a crystallite size of ~15-21 nm range, further confirmed by HRTEM results. SEM images confirmed the well-known nano-size morphology for all the samples. The magnetization measurements show a hard ferromagnetic nature for all specimens within the temperature range of 20-300K. Coercivity, remanent, and saturation magnetization monotonically increased with a reduction in temperature from 300K to 20K. UV-Vis absorbance results show that the band gap energy of CoFe2O4 nanoparticles (NPs) decreases with increasing Gd3+ ion doping and have band gap energy values of 2.47, 2.15, 2,02, 2.00, 1.43 and 1.95 eV for x= 0.00, 0.02, 0.04, 0.06, 0.08, 0.10, respectively in CoGdxFe2-xO4 nanoferrites. The present study reveals that structural, optical band gap and magnetic properties could be altered by monitoring the quantity of gadolinium in cobalt nanoferrites. Bangladesh J. Sci. Ind. Res. 57(3), 173-186, 2022