In this communication, for the first time, we demonstrate the shape-controllable synthesis of molybdenum carbide (Mo2C) nanowires (NWs) and nanosheets (NSs) via direct pyrolysis of their MoOx/p-phenylenediamine hybrid precursors under Ar. We further demonstrate the use of such carbides as a highly active hydrogen evolution reaction electrocatalyst with good durability in acidic solution. It also suggests that the Mo2C NWs exhibit superior activity and durability over the Mo2C NSs. (C) 2014 Elsevier Ltd. All rights reserved.