Synthesis of Nickel-Based Electrocatalysts on Carbon Fiber for Maximum Active Sites Exposed: An Efficient Hydrogen Evolution 3D Electrode

초록

The exploration of high-efficiency electrodes for alkaline water electrolysis is significant in the advancement of hydrogen energy, minimizing the influence of CO2 emission to the environment. Ni-based materials have been evaluated as potential electrocatalysts for hydrogen evolution reaction (HER) because of their promising catalytic activities, low cost, and remarkable durability. In this work, we synthesized a Ni-based metal-organic framework on carbon fiber (CF) through the hydrothermal method, followed by pyrolysis to create Ni metal particles implanted on carbon frameworks (Ni/C/CF). The Ni/C/CF catalyst displayed a higher catalytic efficiency than Ni/C powder. The Ni/C/CF electrode needs an overpotential of 117 mV to achieve 10 mA cm-2 and remarkable durability, which was confirmed by 2000 cycles and 12 h of continuous hydrogen production. This performance was attributed to the effectiveness of CF with a three-dimensional structure, favoring more exposed active sites and efficient electron transport. Moreover, carbon frameworks, inherited from MOF materials, preserve catalytic sites and avoid the aggregation of Ni nanoparticles, maximizing active sites for HER. The results of this work could bring a potential direction for the preparation of transition metal-based materials on CF as efficient non-binder electrodes for HER. Direct synthesis of Ni-MOF-74 on the surface of carbon fiber was achieved.Carbon fiber enhances electrochemical surface area and charge transport properties of Ni/C/CFCarbon skeleton protected and improved active sites for HER.Ni/C/CF binder-free cathode requires only 117 mV to obtain 10 mA cm-2.Ni/C/CF cathode displayed an outstanding stability in alkaline solution.

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