Novel Bi₂S₃/NiCo₂O₄ nanocomposites (BS/NCO) with various mass ratios were prepared using NiCo-MOF as precursor. The morphology, composition and structure of the as-prepared catalysts were studied by different techniques such as FE-SEM, EDX, XRD, FT-IR, VSM and BET. The as-synthesized composite with 20 % Bi₂S₃ (%20 BS/NCO) demonstrated the best performance in reduction reaction of 4-nitrophenol (4-NP). The enhanced catalytic activity of %20 BS/NCO composite compared to the Bi₂S₃ and NiCo₂O₄ can be assigned to the optimized synergistic effects between the two pristine materials. Thermodynamic parameters and the activation energy of the reaction in the presence of %20 BS/NCO composite were calculated by conducting the reaction in various temperatures. Moreover, DFT calculations was used to explore the mechanism of 4-NP reduction in the presence of BS/NCO composite. BS/NCO composite was also used in catalytic reduction of organic dyes.