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

Abstract

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–Mo_xC 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 m² g⁻¹ was achieved for N–Mo_xC, 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.