Template-assisted preparation of imbricate N-Mo_xC nanotubes for the effective electrocatalytic hydrogen evolution reaction

Molybdenum carbide (Mo2C) has become a promising candidate for electrocatalytic hydrogen production from water splitting due to its low price and platinum-like electrocatalytic properties. In this work, Mo2C nanotubes (Mo2C NTs) with ultrathin imbricate structure were successfully synthesized by carburizing polydopamine organic layer covered molybdenum trioxide (MoO3) nanowire templates at elevated temperature through organic-inorganic hybridization. The inner diameter and wall thickness of the as-synthesized Mo2C NTs are about 150 nm and 100 nm, respectively. Two-dimensional Mo2C nanoflakes with a thickness of about 10 nm were composed of nanoclusters with a size of 2 nm. Furthermore, N-MoxC was facilely prepared by nitrogen doping into the prepared Mo2C by chemical vapor deposition and the enhanced electrocatalytic activity was obtained with an overpotential of 120 mV at a current density of 10 mA cm(-2). An enlarged specific surface area of 189 m(2) g(-1) was achieved for N-MoxC, which provides more electrocatalytic active sites for water reduction. More importantly, the interface optimization of Mo2C and MoC was expected to modify the electronic structure and accelerate the electron transfer for improved water splitting performance.