Enhancement in Photoluminescence and Photocatalytic Performances of Solution Combustion Synthesized ZnO Nanoparticles upon Sm Doping

This study explores the synthesis of ZnO nanoparticles through a solution‐combustion route, examining their structural, photoluminescent, and photocatalytic properties upon introducing Sm as a dopant. All synthesized samples display a hexagonal wurtzite structure, with crystallite sizes between 55 and 73 nm. Field‐emission scanning electron microscopy reveals significant sample morphological variation. Diffuse reflectance spectroscopy indicates that doping with Sm 3+ results in a slight decrease in the bandgap energy. The photoluminescence (PL) emission spectra at excitation wavelengths of 325, 350, and 390 nm show broad emission bands spanning from the violet to the green regions of the visible spectrum, attributed to defects in ZnO. Additionally, the PL intensity increases with Sm doping up to 2 mol% Sm, after which it declines. The photocatalytic degradation efficiency improves upon Sm doping up to 3 mol% and thereafter decreases.