Ni(NO3)(3)center dot 6H(2)O has been thermally decomposed to synthesize NiOx (0 < x < 1) and a modified citrate-nitrate route has been employed for LaNiO3-delta synthesis. These metal oxides have been characterized by XRD, SEM, TEM, XPS and UV-vis spectroscopy for the determination of their crystal structures, structural morphologies, oxidation states and optical band gaps. The devices, made of nanocrystalline-composites or nanocomposites, have been fabricated on gold coated soda lime glasses, where the device based on NiOx has been found applicable for UV photo-conducting and LaNiO3-delta has been recognized as a potential IR photo-conducting sensors. Their respective current amplifications have been recorded 8 and 2.2 times more than the dark current at 2 V of DC bias. The UV sensor has been explained by direct band gap semiconducting nature of NiOx and IR sensitivity of LaNiO3-delta was explained in terms oxygen deficiency induced band gap opening.