Dye Degradation Experiments. Photocatalytic experiments using naphthol blue black dye were carried out using 0.05 mg/mL RGO and 50 μM TiO2 colloidal suspensions. The suspensions were irradiated with white light from Xe lamp passing through a 10 cm water filter followed by AM 1.5 filter at 150 mW/cm2.