Considering that the quantum efficiency for the generation of hydrated electrons was 1.5 × 10 -2 under the nanosecond laser pulse excitation, the observed quantum efficiency for C-F bond dissociations using LED light appears remarkably high. This is probably due to the contribution of the direct electron transfer from higher excited states to the decomposition of PFOS in addition to the reaction with hydrated electrons. Similar photocatalytic behaviors were observed with Cu-CdS NCs (Supplementary Fig. ).