Low-temperature synthesized Mo2C and novel Mo2C–MnO2 heterostructure for highly efficient hydrogen evolution reaction and high-performance capacitors

Abstract

Here, a facile and cost-effective way is proposed to synthesize Mo2C nanoparticles and Mo2C/MnO2 heterostructures by utilizing laboratory waste. The Mo2C nanoparticles are well encapsulated by graphitic carbon layers, which provide high cyclic and structural stability to Mo2C. The electrochemical hydrogen evolution reaction (HER) activity and capacitive properties of these samples are studied in detail. Mo2C synthesized at 500 °C exhibits higher HER activity with a Tafel slope of 79 mV dec−1. To further improve the HER activity of Mo2C nanoparticles, the heterostructure of Mo2C and MnO2 is developed. The optimized Mo2C/MnO2 (2:1) heterostructure delivers a current density of 10 mA cm−2 at a low overpotential of 58.3 mV and shows a very low Tafel slope of 36 mV dec−1. It exhibited long-term cyclic stability up to 5000 cyclic voltammetry (CV) cycles. This paper describes a novel and effective method for fabricating noble metal-free HER electrocatalysts utilizing laboratory waste as a carbon precursor.