The oxidative degradation of RGO by UV irradiated TiO2 fundamentally challenges the current paradigm of coupling these materials for aqueous-based photocatalysis and other applications where OH• radicals are present. In fact, the fragmentation of RGO could exacerbate the environmental challenges TiO2-RGO composites are employed to remediate. Because the initial breakdown of the RGO occurs quickly and leads to more recalcitrant compounds that are slower to degrade via OH•, these fragments, if untreated, may enter into the environment.