Drawing upon the outcomes of preliminary optimization trials (Table , ESI), control experiments (S2.8, ESI), DFT calculation and pertinent references in the literature, we proposed the following mechanistic pathway for the photocatalytic trifluoromethylation process (S2.9, ESI). Initiated by blue LED irradiation, the Cu@f-gC3N4 photocatalyst underwent activation, generating positive holes at the valence band and an excess of electrons at the conduction band on its surface.