Journal of Cleaner Production | 2019
Waste plastic derived carbon supported Mo2C composite catalysts for hydrogen production and energy storage applications
Abstract
Abstract The valuable approach to produce hydrogen as fuel for efficient and clean energy source is electrochemical water splitting. Synthesis of efficient and economic catalysts for hydrogen evolution reaction (HER) is necessary for commercial scale production of hydrogen. The essential and successive path in the field of energy transformation and capacitors are the synthesis of the high performance electrodes. Herein, we report the synthesis of molybdenum carbide (MoC/Mo2C) via in-situ carburization route. The work reports utilization of waste plastics for the synthesis of molybdenum carbide carbon nanocomposites, which are subsequently used for the hydrogen production and energy storage applications. The environmental issues caused by the waste plastics and the limitations of recycling/reuse has been addressed. The effect of carburization temperature, the role of the initial amount of carbon on phase formation of molybdenum carbide and electrochemical activities has been discussed. The XRD results confirm the pure phase formation of Mo2C at 700 and 800\u202f°C. The adherent nature of residual carbon determined by Raman spectroscopy and HRTEM analysis in the synthesized powders affect the electrochemical properties, hydrogen evolution reaction (HER), electric double layer capacitance (EDLC) as well as electrochemical impedance spectroscopy (EIS). The amount of adherent residual surface carbon determined by TGA analysis plays imperative role in protecting the carbide particles from oxidation and firmly contributes to the electrochemical activity. The synthesized material shows the higher stability up to 2000 cyclic voltammetry (CV) cycles in the voltage range 0.2 to\xa0−0.3\u202fV. The powders synthesized at higher temperature shows the higher double layer capacitance (Cdl) and specific capacitance to the tune of 19.46\u202fmFcm−2 and 55.6\u202fFg-1, respectively. The graphitic carbon coating obtained at relatively higher temperature affects the storage capacity/retention as well as the charge transfer resistance.