Steel slag nanocomposite was synthesized in this study using a solvothermal preparation technique from raw electric arc furnace (EAF) slag. XRF, SEM, FTIR, and UV–Vis spectroscopy techniques were used to characterize the prepared nanocomposite. The XRF result shows a high amount of SiO2 and Fe2O3 constituent in the slag with a small weight percentage of TiO2. The prepared slag nanocomposite was utilized for methylene blue (MB) dye degradation. The Photodegradation result from the study indicated an optimum degradation efficiency of 77.07 % at a 40 min irradiation time. The effect of pH variation and catalyst dosage on photodegradation was studied. The results reveal that photodegradation of the dye occurs best in an alkaline solution and that increasing the catalyst dosage above the reaction threshold reduces the degradation efficiency.