Rational design of highly efficient and durable electrocatalysts for hydrogen evolution reaction (HER) is of prime importance for renewable and sustainable energy. Herein, PtNi nanodentrites (PtNi NDs) were facilely synthesized in oleylamine (OAm) by a one-pot solvothermal method, using melamine and cetyltrimethylammonium chloride (CTAC) as co-structure-directing agents. The obtained catalyst showed superior catalytic activity and enhanced durability for HER relative to commercial Pt/C, home-made PtNi3 nanocrystals (NCs) and Pt3Ni NCs both in alkaline and acidic media. The enhanced HER activities are attributed to bimetallic synergies and interface structures in PtNi NDs. This work provides an effective strategy to prepare highly efficient and durable electrocatalysts for HER. (C) 2018 Elsevier Inc. All rights reserved.