Electrochemical water splitting, which is economical and sustainable, has been considered as one of the most potential methods to produce large amounts of hydrogen with high purity. However, the development of uniformly dispersed electrocatalysts with robust catalytic activity and high stability for electrochemical water splitting still faces great challenges. In this study, poly(ionic liquid) (PIL) was used as a bridge between the polyoxometallate and the reduced graphene oxide (RGO) to anchor Mo uniformly on the surface of the RGO. As a result, the Mo2C-RGO exhibits excellent activity in hydrogen evolution reactions in acidic media with a small overpotential of 99 mV to drive 10 mA cm(-2) and a low Tafel slope (54.6 mV dec(-1)) in acidic solution, and no significant degradation was observed after 20 h of operation. This facile strategy offers new opportunities to accurately design functional 2D materials with unique properties.