The NiO/ZnO/Fe₂O₃ ternary nanocomposites with different molar ratios (1:1:1), (2:1:1), (3:1:1) and (4:1:1) were synthesized by co-precipitation method. The morphological, structural, optical, luminescent and photocatalytic reduction properties of the synthesized nanocomposites were investigated. The XRD study confirmed the presence of NiO, ZnO and Fe₂O₃ in the as-synthesized nanocomposites. The as-synthesized nanocomposites exhibited violet, blue, blue-green, green and orange-red emission bands which are ascribed to defect-related transitions. All the as-synthesized nanocomposites achieved near white emission. A high CRI with cool white light was exhibited by these samples. This study shows that all the as-synthesized nanocomposites can potentially perform as UV-activated phosphors for cool white LED. In addition, the NiO/ZnO/Fe₂O₃ nanocomposite having molar ratio (4:1:1) exhibited outstanding photocatalytic activity towards the reduction of Methylene Blue (MB) and Methyl Orange (MO) and efficient recoverable magnetic nanocatalyst behavior having potential applications in environment protection.