Title: Carbonyl Nickel Nanoparticles: Synthesis, Properties, and Applications Abstract: Carbonyl nickel nanoparticles (Ni(CO)4 NPs) represent a unique class of nickel-based nanomaterials with distinct chemical and physical properties. This article reviews the synthesis methods, characterization techniques, and diverse applications of carbonyl nickel nanoparticles, emphasizing their role in catalysis, materials science, and environmental technology. 1. Introduction: Carbonyl...