Guanine-Assisted Contrived Low Pt-Integrated Mo2C/C for Hydrogen Evolution Reaction

Abstract

Due to the high cost of the available Pt electrocatalysts, the large-scale water electrolysis production of hydrogen has been hindered. Hydrogen generation via electrochemical water splitting is a renewable energy essential to a sustainable society, creating a distinct material interface that shows Pt-like properties with long-term stability crucial to hydrogen evolution reactions (HERs). Here, we synthesized the guanine-assisted facile synthesis of 1 wt % Pt/Mo2C/C having a layered type morphology via solid state calcined process followed by chemical reduction. The well-developed 1 wt % Pt/Mo2C/C heterostructure is analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES) to understand the percentage of Pt doped on Mo2C/C. The as-synthesized 1 wt % Pt/Mo2C/C heterostructure exhibits a better HER activity than a commercial Pt/C with a small overpotential of 19 mV to reach a current density at 10 mA cm-2 with a Tafel slope of 28 mV/dec. The catalyst 1 wt % Pt/Mo2C/C shows a long-term stability of 42 h in 0.5 M H2SO4. The layered sheet structure with the N-doped carbon (C) nanosheet, encapsulating well-dispersed Pt within the layers, significantly enhances the reaction kinetics of the 1 wt % Pt/Mo2C/C. This design creates a synergistic effect among Mo2C, Pt, and the carbon matrix, improving catalytic performance. Theoretical calculations using the density functional theory (DFT) indicate the active sites for hydrogen evolution on Pt-integrated Mo2C/C. The 1 wt % Pt/Mo2C/C possessed a significantly reduced Delta G H* value (-0.06 eV) as compared to the pristine Mo2C/C material (Delta G H* = 0.34 eV), suggesting a higher catalytic activity. This simple method offers a fresh means to make clearly defined carbides and sheds light on creating low-Pt catalysts for a scalable HER.