pone.0328646.t001 -

Industrial wastewater contaminated with organic dyes poses significant environmental and health risks. Developing effective and eco-friendly removal methods is crucial to mitigate the harmful impact of dye pollution. This study explores the green synthesis and application of strontium oxide (SrO) nanoparticles and chitosan-encapsulated strontium oxide (CS-SrO) nanocomposite as adsorbents for the removal of cationic and anionic dyes from aqueous solutions. Characterization revealed that the SrO nanoparticles exhibited a sharp localized surface plasmon resonance (LSPR) peak at 274 nm, while the CS-SrO nanocomposite depicted a broad LSPR peak between 230–280 nm. XRD analysis confirmed the face-centered cubic structure of the SrO nanoparticles, with an average crystallite size of 32 nm. Detailed dye removal studies revealed that the SrO nanoparticles achieved up to 80% removal of the cationic crystal violet dye, while the CS-SrO nanocomposite demonstrated 81% removal of the anionic methyl orange dye under optimized conditions. Further investigations into adsorption kinetics, isotherms, and thermodynamics provided insights into the mechanisms governing the dye removal processes. This work contributes to the advancement of green nanotechnology for environmental remediation purposes. These findings pave the way for the development of practical applications in water purification and pollution control strategies.