In summary, we have outlined and rationalized via advanced experimental characterization and modeling an efficient strategy for the para-functionalization of arenes by using an atomically dispersed Cu photocatalyst which does not require the presence of a directing group. This study is articulated into two key segments: first, the formulation and synthesis of a Cu-based catalyst with atomic dispersion of coordinated Cu sites on an aryl-amino-substituted graphite carbon nitride; second, the application of this photocatalyst for accomplishing an unprecedented para-selective C-H trifluoromethylations of electron-poor arenes.