A nanocomposite of ZnCo₂O₄/N-doped g-C₃N₄ was synthesized using the hydrothermal method and used as a photocatalyst to degrade Rhodamine B (RhB) under visible light. The nanocomposite was characterized using XRD, FTIR, FE-SEM, EDS, TEM, UV–Vis DRS, and BET/BJH techniques. XRD analysis confirmed the successful synthesis of cubic ZnCo₂O₄ and nanolayered g-C₃N₄. BET/BJH analysis showed all samples exhibited Type-III isotherms and H3-type hysteresis loops. FTIR and EDX confirmed the formation of the nanomaterials. UV–Vis DRS results indicated that the loading of ZnCo₂O₄ on N-doped g-C₃N₄ shifted the absorption edge to longer wavelengths. The morphology showed sufficient distribution of ZnCo₂O₄ nanoparticles on g-C₃N₄ nanosheets. Photocatalytic degradation results showed that the efficiency could be enhanced by optimizing operating conditions, including irradiation time, catalyst dosage, RhB concentration, and solution pH. The ZnCo₂O₄/N-doped g-C₃N₄ nanocomposite showed the highest photodegradation efficiency of 92.34% RhB degradation in 60 min. Scavenging studies indicated that hydroxyl radicals (·OH) played a main role in the photodegradation process. Kinetic studies showed that the photodegradation of RhB followed a pseudo-first order kinetic model. Recyclability studies showed that the nanocomposite retained 83.38% of its initial activity after five cycles. At optimum conditions, the COD removal efficiency was 79.55%, indicating most dye molecules were degraded. The current system is an efficient and effective approach for water contaminant remediation. Keywords: Photocatalysis; Zinc cobaltite; Graphitic carbon nitride; Rhodamine B; Hydrothermal; Visible light.A nanocomposite of ZnCo₂O₄/N-doped g-C₃N₄ was synthesized using the hydrothermal method and used as a photocatalyst to degrade Rhodamine B (RhB) under visible light. The nanocomposite was characterized using XRD, FTIR, FE-SEM, EDS, TEM, UV–Vis DRS, and BET/BJH techniques. XRD analysis confirmed the successful synthesis of cubic ZnCo₂O₄ and nanolayered g-C₃N₄. BET/BJH analysis showed all samples exhibited Type-III isotherms and H3-type hysteresis loops. FTIR and EDX confirmed the formation of the nanomaterials. UV–Vis DRS results indicated that the loading of ZnCo₂O₄ on N-doped g-C₃N₄ shifted the absorption edge to longer wavelengths. The morphology showed sufficient distribution of ZnCo₂O₄ nanoparticles on g-C₃N₄ nanosheets. Photocatalytic degradation results showed that the efficiency could be enhanced by optimizing operating conditions, including irradiation time, catalyst dosage, RhB concentration, and solution pH. The ZnCo₂O₄/N-doped g-C₃N₄ nanocomposite showed the highest photodegradation efficiency of 92.34% RhB degradation in 60 min. Scavenging studies indicated that hydroxyl radicals (·OH) played a main role in the photodegradation process. Kinetic studies showed that the photodegradation of RhB followed a pseudo-first order kinetic model. Recyclability studies showed that the nanocomposite retained 83.38% of its initial activity after five cycles. At optimum conditions, the COD removal efficiency was 79.55%, indicating most dye molecules were degraded. The current system is an efficient and effective approach for water contaminant remediation. Keywords: Photocatalysis; Zinc cobaltite; Graphitic carbon nitride; Rhodamine B; Hydrothermal; Visible light.