The present study reports, for the first time, both a facile synthesis for ternary Cu2WS4 nanocubes, which were synthesized by a simple and low-cost hot-injection method, and the hydrogen evolution reaction at a biomembrane-like polarized water/1,2-dichloroethane interface catalyzed by Cu2WS4 nanocubes. The rate of hydrogen evolution reaction is increased by about 1000 times by using Cu2WS4 nanocubes when compared to an uncatalyzed reaction.