Herein, we achieved successful synthesis of 2D Cu2S nanosheets (NS) with a thickness of 1.2 nm by a novel strategy. The key to obtain ultra-thin Cu2S NS was the use of a unique sulfur precursor which not only supplied sulfur in a controlled manner, but also directed the formation of a 2D structure. The as-prepared Cu2S NS were proved to be effective cocatalysts for photocatalytic hydrogen production. The H2 production rate of Cu2S NS/TiO2 reached 1430.4 μmol g(-1) h(-1), which was 4.9 times higher than that of TiO2.