In this study, composites of TiO2/nanographene platelets (NGP) were investigated for removing organic pollutants in aqueous solution using catalytic activity. Photocatalytic, sonocatalytic, and sonophotocatalytic techniques were used in the present study. TiO2/NGP composites were successfully synthesized using a co-precipitation method. The contents of NGP were varied from 5, 10, and 15 weight percent (wt.%) in the composites. X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were used to investigate the structures and thermal properties of samples. The anatase form of the samples was detected, which was attributed to the existence of TiO2 materials. The maximum adsorption capacity of the composites was 30.4 mg/g. The catalytic activities were evaluated for the degradation of methylene blue. From the catalytic activity, it was confirmed that the TiO2/NGP composite having 10 wt.% NGP exhibited better catalytic performance than other variations by wt.% of the TiO2/NGP samples or pure TiO2. Furthermore, the influence of scavengers of reactive species on the photo-, sono-, and sonophoto-catalytic activity was investigated.