NiO nanoparticles have been synthetized by calcination of layered double hydroxides (LDHs) precursors prepared using dimethylamine (DMA) as a precipitating agent. The incorporation of Ce and La oxides to the structure was investigated. The samples were characterized by element chemical analysis, powder X-ray diffraction, FT-IR spectroscopy, thermal analysis and specific surface area analysis. Furthermore, the optical band gaps of the semiconductor samples were estimated by ultraviolet-visible diffuse reflectance spectroscopy. The results showed that it is possible to obtain Ni-LDHs precursor with good crystallinity and a small crystal size, which can be used as precursors of NiO nanoparticles with ≈3.7 nm of crystal size. The semiconductors obtained have good values of band gaps with rather large specific surface areas, which make them suitable for their use as photocatalysts.