Electrocatalytic hydrogen evolution reaction (HER) is a green approach to produce high-quality hydrogen fuel. Developing efficient electrocatalyst is the key to realize cost-effective HER. Pt is the state-of-the-art HER catalyst so far. However, the use of Pt for HER is limited by its high cost. Thus, it is essential to lower down the usage of Pt in the electrocatalyst by improving the intrinsic activity of Pt. In this work, we propose to achieve this goal by introducing synergistic interaction between Pt and substrate material (NiS2). The favorable synergy interaction can modify the d band structure of Pt (111) facet and modulate the hydrogen adsorption on Pt (111), which enhances the intrinsic electrocatalytic activity of Pt. The effectiveness of this strategy is demonstrated with both experimental and theoretical investigations. (C) 2020 Elsevier Inc. All rights reserved.