In this work, the synthesis of pure and (Ce, Ag) co-doped ZnO has been successfully accomplished by a solvothermal process. The synthesized samples were characterized by ultraviolet–visible spectroscopy (UV-Vis), X-ray diffraction spectroscopy (XRD) and scanning electron microscopy (SEM). The photocatalytic ability of the samples is estimated through degradation of tartrazine in aqueous solution under photocatalytic conditions. The degradation study carried out for a reaction period of 90 minutes and a free pH of solution as 6,found dye degradation is 44.82% for pure ZnO and 98.91% for (Ce, Ag) co-doped ZnO samples. These results suggest excellent photocatalytic ability of (Ce, Ag) co-doped ZnO. Tartrazine mineralization was studied by calculating the degradation of Chemical oxygen demand (COD). Therefore, with our photocatalysts, the effect of operating parameters such as catalyst dose, initial concentration of tartrazine, initial reaction pH and nature of light source has been optimized for tartrazine degradation as a function of time. The reusability of ZnO and (Ce, Ag) co-doped ZnO2 catalysts has also been studied and its photocatalytic efficiency was found to be unchanged ever after 6 cycles of use. The mechanism of photocatalytic activity was proposed in this work.

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In recent years, nosocomial infections and antibiotic resistance are major public health problems. Nanotechnology should open new avenues to treat and prevent diseases. In this research work, iron-doped tin dioxide (Fe-SnO2) nanoparticles have been synthesized by the chemical co-precipitation method. X-ray diffraction analysis confirms the formation of nanocrystalline SnO2 single phase with Fe favoring grain growth, the crystallite size increases from 13 up to 29 nm. FT-infrared spectroscopy analysis shows the presence of peaks characteristic of the SnO2 phase. Ultraviolet-visible spectroscopy analysis indicates Fe doping induces red-shift of SnO2 bandgap. Morphological observations by scanning electron microscopy reveal randomly arranged irregular-sized compact grains with sponge-like microstructure. Energy dispersive X-ray spectroscopy analysis (EDX) confirms the purity of Fe-doped SnO2. Bacteria produce siderophores capable of capturing iron, a necessary nutrient. For this reason, SnO2 has been doped particularly with Fe to facilitate the entry of nanoparticles into the bacterial cell and improve its antibacterial activity. Fe-SnO2 nanoparticles exhibit significant antimicrobial and anti-biofilm activities against all tested microorganisms; it is found that biofilm eradication of the tested strains is higher than 90%. The fabricated Fe–SnO2 nanopowders have potential as antiseptics and disinfectants that will eliminate, kill, or inactivate microorganisms usually found on inert surfaces such as soil, walls, medical-surgical equipment, to prevent nosocomial infections in hospitals.

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