Construction of hierarchical NiFe-LDH/FeCoS 2 /CFC composites as efficient bifunctional electrocatalysts for hydrogen an
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Construction of hierarchical NiFe-LDH/FeCoS2/CFC composites as efficient bifunctional electrocatalysts for hydrogen and oxygen evolution reaction Zewu Zhang1, Jiamin Zhou2 Gang Xu2,* 1 2
, Hanlin Wei2, Yifan Dai1, Shijia Li1, Haojun Shi1, and
School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing 21167, People’s Republic of China School of Environmental and Chemical Engineering, University of Shanghai, Shanghai 200444, People’s Republic of China
Received: 1 June 2020
ABSTRACT
Accepted: 29 August 2020
Efficient design and preparation of cost-effective and binder-free bifunctional electrocatalysts to accelerate the hydrogen and oxygen evolution reaction (HER and OER) are critical for overall water splitting. In this work, 3D hierarchical NiFe-LDH/FeCoS2/CFC electrodes were synthesized for the first time. The carboxyl groups derived from acid treating promote the homogeneously coated FeCoS2 on CFC, giving rise to the strongly coupled FeCoS2/CFC hybrid. The NiFe-LDH exhibited the vertical growth feature on the FeCoS2/CFC composite, which can efficiently expose the active edges sites. Due to unique structure and synergistic effect between the components, the NiFe-LDH/FeCoS2/CFC exhibits significant electrocatalytic activity and stability under alkaline environments, with overpotentials of 190 and 308 mV to achieve 10 mA cm-2 for OER and HER, respectively, providing it as a promising electrocatalyst for water splitting reaction. In addition, we deeply studied the synergistic catalytic mechanism of NiFe-LDH/FeCoS2/CFC, explaining the reasons leading to the improved catalytic performance of HER and OER.
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Springer Science+Business
Media, LLC, part of Springer Nature 2020
Handling Editor: Dale Huber. Zewu Zhang and Jiamin Zhou have contributed equally to this work.
Address correspondence to E-mail: xugang@shu.edu.cn
https://doi.org/10.1007/s10853-020-05182-5
J Mater Sci
GRAPHIC ABSTRACT
Introduction The sustainable production of hydrogen through electrocatalytic water splitting is expected to be a promising approach for addressing the forthcoming energy consumption and associated environmental pollution [1, 2]. The water splitting reaction is composed of two half reactions, namely oxygen and hydrogen evolution reaction (OER and HER) [3]. Nevertheless, these two half reactions suffer from both intrinsically sluggish kinetics and unfavorable thermodynamic, which requires effective catalysts to accelerate the reaction process [4]. At present, precious Pt-based catalysts are considered as the state-of-the-art HER catalysts, while Ir/Ru-based oxides are used as the benchmark for OER electrocatalysts [5–7]. Unfortunately, the exorbitant price and low abundance of these catalysts limit the large-scale commercial applications [8]. Consequently, it is highly desired to develop effective electrocatalysts by using non-noble metal. Considering catalytic activity, durability and material cost, transition metals chalcogenides (TMCs) have been regarded as a class of advantageous HER catalysts
