Synthesis of Titanium Dioxide-Nickel/Nickel Oxide Quasi Core-Shell Nanoparticles using Solution Plasma

In this study, TiO₂@Ni/NiO quasi core-shell nanoparticles (NPs) were synthesized using solution plasma for future photocatalytic applications. X-ray diffraction analysis confirmed that all samples contained TiO₂, Ni, and NiO. Scanning and scanning transmission electron microscopy images revealed that the quasi core-shell NPs were spherical with smooth surfaces and consisted of larger TiO₂ NPs partially covered by smaller Ni/NiO NPs. Transmission electron microscopy images showed degradation of PVP forming visible solid precipitates at 0.25% (w/v) PVP concentration. X-ray photoelectron spectroscopy (XPS) analysis indicates that the N 1s peak at 399.3–400.1 eV is contributed by nitrogen atom in the PVP molecule. The optimal PVP concentration was determined to be in the range of 0.05%–0.15% (w/v) PVP; a higher concentration of 0.25% (w/v) PVP led to degradation of PVP.