Sub-3 nm NiO nanoparticles: Controlled synthesis, and photocatalytic activity

Organic solution-phase reaction under oxygen atmosphere for synthesis of single crystalline and uniform sub-3   nm NiO nanoparticles has been developed. Larger NiO nanoparticles with diameter about 26   nm can be also prepared by seed-mediated growth method. Optical property of the NiO nanoparticles was conducted by means of UV–vis spectrum, exhibiting obviously blue shift compared with the bulk counterpart due to the quantum confinement effect . The photocatalytic activity in degradation of rhodamine B was also investigated. The results showed that the sub-3   nm NiO nanoparticles exhibit much higher activity for UV-photodegradation than the as-synthesized larger NiO particles and commercial 30   nm nanopowder .