X-ray crystallographic structural Profiling of Polyvinyl Alcohol (PVA) caped Nickel Oxide Nanoparticle

• 87 % pure NiO phase with crystallinity of 47.21 %. • Hexagonal structure with lattice parameters of a = b = 2.955 Å, c = 7.2434 Å. • Angular parameters α=β= 90 ° and γ= 120 °. • Average dislocation density of 0.00206 nm⁻², lattice strain of 0.27 %. • Uniform spherical morphology with average particle size 48 nm. A unique simple co-precipitation method was developed for synthesizing highly crystalline nickel oxide nanoparticles (NiO NPs) where poly vinyl alcohol (PVA) solution as capping agent. Rietveld refinement analysis explored whole powder pattern fitting (WPPF) method confirmed resulting nanoparticles (NPs) consist of 87 % pure NiO phase. X-ray diffraction (XRD) analysis revealed a distinct hexagonal NiO crystalline phase, with lattice parameters a = b = 2.955 Å, c = 7.2434 Å, and angles α=β= 90 ° and γ=120 ° The predominant (0 1 2) plane, associated with the strongest diffraction at 2θ= 43.228 °, underscored the crystallinity of the material. Key crystallographic parameters include an average dislocation density of 0.00206 nm⁻², lattice strain of 0.27 %, a unit cell volume of 54.776 ų, a specific surface area of 41.435 m²/g, micro-strain of 0.00288, crystallinity index of 2.174 and an atomic packing factor (APF) of 64.9 %. Remarkably, 47.21 % of the synthesized NiO NPs demonstrated a crystallinity closely aligned with ICDD standard. Transmission electron microscopy (TEM) imaging showing a uniform distribution of NPs throughout the inner core structure spherical in shape and an average particle size of 48 nm in interface. Without nickel and oxygen signal, no signals were found that conform the purity of NiO NPs where nickel and oxygen were 67 % and 33 %. This study offers a detailed analysis of the enhanced crystallinity through comprehensive approaches.