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.