Abstract: NiO nanoparticles were synthesized by a sol-gel technique. Ni(NO₃)₂.6H2O and citric acid were employed as starting raw materials. Then, the obtain result calcined at 550 0C for 5 h. The phase composition and the structure of the calcined products were investigated by X-ray diffraction and scanning electron microscopy techniques, respectively. XRD patterns exhibit six (111), (200), (220), (311), (222) and (400) characteristic peaks of cubic crystalline NiO. Then The Ni-porphyrin immobilized on surface of NiO and the potential of the obtained photocatalysts in degradation of methylene blue dye was studied under visible irradiation.