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Supported Heterostructured MoC/Mo₂C Nanoribbons and Nanoflowers as Highly Active Electrocatalysts for Hydrogen Evolution Reaction

Author:
Wei, Zhaoqian, Hu, Xiao, Ning, Shunlian, Kang, Xiongwu, Chen, Shaowei
Source:
ACS sustainable chemistry & engineering 2019 v.7 no.9 pp. 8458-8465
ISSN:
2168-0485
Subject:
catalysts, catalytic activity, copper, copper nanoparticles, electrical conductivity, electrochemistry, electron transfer, foams, foil, hydrogen production, molybdenum, nanoflowers, nickel, nitrogen content, pH, potassium hydroxide, pyrolysis, sulfuric acid, temperature
Abstract:
Development of low-cost and high-efficiency electrocatalysts for hydrogen evolution reaction is a critical step toward sustainable water splitting. Herein, in situ growth of heterostructured MoC/Mo₂C nanoribbons and nanoflowers on copper foam (MoₓC/Cu), copper foil, and nickel foam (MoₓC/Ni) are prepared via a two-step method: hydrothermal preparation of molybdenum precursors followed by pyrolysis at controlled temperatures. The MoₓC/Cu hybrids are found to exhibit an excellent catalytic activity, as compared to the MoₓC/Ni and Cu foil counterparts, and the sample prepared at 750 °C stands out as the best among the series with a low overpotential of 169 mV to reach the current density of 200 mA cm–² in 1 M KOH, and 194 mV in 0.5 M H₂SO₄, and the corresponding Tafel slopes of 98 and 74 mV dec–¹, respectively. The electrocatalytic activity is also found to vary with the Mo²⁺/Mo³⁺ and N contents in the samples that impact the electrical conductivity and electron-transfer kinetics of the hydrogen evolution reaction. Results suggest that MoC/Mo₂C heterostructured materials supported on copper foam may be a viable candidate to catalyze hydrogen evolution reaction in a wide range of pH.
Agid:
6422609