Influence of Metal (al, Mg, Sm, and Cu) Dopants on Structural, Optical, Magnetic, and Antimicrobial Properties of ZnO Nanopowders Synthesized by Coprecipitation Method

Pure and metal-doped ZnO nanopowders with composition formula M0.04Zn0.96O (where M = Al, Mg, Sm, and Cu) are synthesized using the coprecipitation method. The structural characterization of synthesized powders is investigated using X-ray diffraction and the results confirm the hexagonal wurtzite structure without any additional phases. The change in structural parameters of ZnO with dopants is estimated using X-ray peak profile analysis. The structural characterization is further analyzed by Fourier-transform infrared spectroscopy. The size and morphology of the synthesized powders are analyzed by a field-emission scanning electron microscope, which also evidences the formation of uniform nanostructures with quasi-spherical and hexagonal shapes. Moreover, the elemental composition of these metal-doped nanotructures is determined by energy-dispersive X-ray measurements. UV-vis spectroscopy is used to determine the energy bandgap of ZnO nanopowders. A vibration sample magnetometer is employed to measure the samples' magnetic properties, and dopants are found to induce distinct magnetic behaviors in ZnO. The antimicrobial activity of the synthesized powders is measured using the well diffusion method. It is observed that the introduction of dopant metals leads to increased microbial activity. Among the doped ZnO variants, Al-doped ZnO exhibits the highest level of microbial activity compared to pure ZnO and other samples.