<p>A series of composites AC-ZnO(1-x)/Bi₄Ti₃O₁₂(x) (30, 50, and 70 wt. %) with enhanced optical properties are fabricated using a cost-effective molten salt synthesis involving ethanol as solvent to create a varying bonding between pure Bi₄Ti₃O₁₂ (BTO) and activated carbon (AC) prepared from potato plant waste (PPW). X-ray diffraction analysis confirms the high crystallinity of BTO, and the appearance of ZnO and ZnC reflects ethanol's effectiveness in the preparation of composites. Scanning electron microscopy with energy-dispersive X-ray spectroscopy reveals the formation of BTO plates homogeneously dispersed onto AC layers. Fourier-transform infrared spectroscopy analysis manifests characteristic vibration bands thus confirming the chemical composition of AC-ZnO/BTO composites. The presence of active modes in Bi₄Ti₃O₁₂ nanocrystals as investigated by Raman spectroscopy confirms the orthorhombic structure and the respective bands of carbon materials for the composite AC-ZnO (0.7) / BTO (0.3). Brunauer–Emmett–Teller analysis reflects a large surface area with an increase in AC-ZnO amount up to 324.80 m²/g. The photocatalytic activity for the degradation of cationic organic dye (Rhodamine B) is found to be mainly influenced by the ratio of AC-ZnO:BTO and the exposure duration, with the PPW-ZnO content having a significant impact. The AC-ZnO (0.7) / BTO (0.3) demonstrates the best photocatalytic performance, reaching 99.9% after 20 min. A plausible photocatalytic process for RhB over AC-ZnO (0.7) / BTO (0.3) composite is proposed based on the active species trapping experiments. This research designed a novel facile method for fabricating semiconductor-based activated carbon composites with improved photocatalytic performance for the degradation of organic pollutants in contaminated water.</p>