Figure 4

C 1s X-ray photoelectron spectroscopy (XPS) spectra of GO0.1/TO0.08 membranes after ultraviolet (UV) irradiation for (a) 0 days, (b) 2 days and (c) 5 days. (d) Ti2p XPS spectra of GO0.1/TO0.08 membranes after UV irradiation for 0–5 days. GO, graphene oxide; TO, titania.