In this study, BiOCl-Fe2O3 nanocomposite was synthesized by mixing 1:1 ratio of pre-prepared BiOCl and Fe2O3 in 100 mL of H2O using Cocos nucifera (coconut milk) as a green fuel through the microwave irradiation method. X-ray diffraction analysis (XRD), Scanning electron microscopy (SEM) with, Fourier transform infrared spectroscopy (FTIR), UV–vis spectroscopy(UV–vis), and photoluminescence (PL) spectroscopy analysis were used to determine the structure, morphology, and optical features of synthesised nanocomposites. The characterized composites were used to dye degradation and electrochemical activity. Synthesized BiOCl-Fe2O3were degraded methylene blue (MB) 96.2 % in 105 min irradiation of visible light. The BiOCl-Fe2O3exhibits significant catalytic activity towards dopamine(DA) under optimal conditions. Cyclic Voltammetry(CV) and Linear sweep voltammetry (LSV) with different concentrations of DA was studied. These results indicate that this BiOCl-Fe2O3 is an effective approach for the precise and reliable identification of DA signals in biological samples.