core-shell structured CdS@C3N4 photocatalyst with a 4 nm thick shell was prepared using self-assembly, and its structure, composition and morphology were characterized in detail. The hybrid visible-light catalyst exhibited a high photocatalytic performance for oxidative coupling of amines under atmospheric conditions, and robust product selectivity up to > 99% for photodriven oxidation of various amines to corresponding imines was achieved. It was confirmed using Hammett-type plots and radical trapping experiments that steric effects and the formation of O-center dot(2)- are critical for photocatalytic conversion of the investigated substrates, and the related catalytic mechanism is presented.