Solvothermal access to rich nitrogen-doped molybdenum carbide nanowires as efficient electrocatalyst for hydrogen evolution reaction

Rich N-doped molybdenum carbide (Mo2C) nanowires for hydrogen evolution reaction (HER) have been prepared by a facile calcination-solvothermal treatment utilizing inorganic-organic hybrid MoOx/aniline as precursor. Firstly, MoOx/aniline nanowires provide one-dimensional nanostructure and N element for the synthesis of N-doped Mo2C through calcination process. XRD and SEM show that uniform N-doped Mo2C nanowires with beta-Mo2C phase can be obtained after calcination of 750 degrees C. The electrocatalytic measurements show N-doped Mo2C nanowires of 750 degrees C exhibit the better activity compared with other samples at 650 degrees C, 850 degrees C and 950 degrees C. Furtherly, ammonium-hydrazine solvothermal process has been used to optimize the N-doping degree of N-doped Mo2C of 750 degrees C. XRD shows that rich N-doped Mo2C nanowires contain the crystalline phase structure, which can be identified by HRTEM. XPS, EDX and elemental mapping data reveal the good distribution and valence of Mo, C and N. The electrocatalytic measurements confirm that rich N-doped Mo2C possesses the lower overpotential, smaller Tafel slope, larger double-layer capacitances and excellent long-term stability after 5000 cycles than other samples, which may be attributed to ammonium-hydrazine solvothermal process. Therefore, Mo-based inorganicorganic hybrid nanostructure may be a promising precursor for excellent HER electrocatalysts through a facile calcination-solvothermal treatment. (C) 2017 Elsevier B.V. All rights reserved.