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Editorial Issue
The Nano Research Young Innovators (NR45) Awards in nanocatalysis
Nano Research 2022, 15 (12): 9961-9966
Published: 29 November 2022
Downloads:140
Research Article Issue
Interface construction of NiCo LDH/NiCoS based on the 2D ultrathin nanosheet towards oxygen evolution reaction
Nano Research 2022, 15 (6): 4986-4995
Published: 10 March 2022
Downloads:71

Carbon-free hydrogen as a promising clean energy source can be produced with electrocatalysts via water electrolysis. Oxygen evolution reaction (OER) as anodic reaction determines the overall efficiency of water electrolysis due to sluggish OER kinetics. Thus, it’s much desirable to explore the efficient and earth-abundant transition-metal-based OER electrocatalysts with high current density and superior stability for industrial alkaline electrolyzers. Herein, we demonstrate a significant enhancement of OER kinetics with the hybrid electrocatalyst arrays in alkaline via judiciously combining earth-abundant and ultrathin NiCo-based layered double hydroxide (NiCo LDH) nanosheets with nickel cobalt sulfides (NiCoS) with a facile metal-organic framework (MOF)-template-involved surface sulfidation process. The obtained NiCo LDH/NiCoS hybrid arrays exhibits an extremely low OER overpotential of 308 mV at 100 mA·cm−2, 378 mV at 200 mA·cm−2 and 472 mV at 400 mA·cm−2 in 1 M KOH solution, respectively. A much low Tafel slope of 48 mV·dec−1 can be achieved. Meanwhile, with the current density from 50 to 250 mA·cm−2, the NiCo-LDH/NiCoS hybrid arrays can run for 25 h without any degradation. Our results demonstrate that the construction of hybrid arrays with abundant interfaces of NiCo LDH/NiCoS can facilitate OER kinetics via possible modulation of binding energy of O-containing intermediates in alkaline media. The present work would pave the way for the development of low-cost and efficient OER catalysts and industrial application of water alkaline electrolyzers.

Research Article Issue
Highly active sites of low spin FeN4 species: The identification and the ORR performance
Nano Research 2021, 14 (1): 122-130
Published: 05 January 2021
Downloads:28

Over recent years, catalytic materials of Fe-N-C species have been recognized being active for oxygen reduction reaction (ORR). However, the identification of active site remains challenging as it generally involves a pyrolysis process and mixed components being obtained. Herein Fe3C/C and Fe2N/C samples were synthesized by temperature programmed reduction of Fe precursors in 15% CH4/H2 and pure NH3, respectively. By acid leaching of Fe2N/C sample, only single sites of FeN4 species were presented, providing an ideal model for identification of catalytic functions of the single sites of FeN4 in ORR. A correlation was conducted between the concentration of FeN4 in low spin state by Mössbauer spectra and the kinetic current density at 0.8 V in alkaline media, and such a structure-performance correlation assures the catalytic roles of low spin FeN4 species as highly active sites for the ORR.

Research Article Issue
Highly efficient K-Fe/C catalysts derived from metal-organic frameworks towards ammonia synthesis
Nano Research 2019, 12 (9): 2341-2347
Published: 23 March 2019
Downloads:22

Fe-based catalysts have been discovered as the best elementary metal-based heterogeneous catalysts for the ammonia synthesis in industrial application during the last century. Herein, a novel and scalable strategy is developed to prepare the K-promoted Fe/C catalyst with extremely high Fe loading (> 50 wt.%) through pyrolysis of the Fe-based metal-organic framework (MOF) xerogel. The obtained K-Fe/C catalysts exhibited superior activity and stability towards ammonia synthesis. The weight-specific reaction rate of Fe/C with K2O as promoter can achieve 12.4 mmol·g-1·h-1 at 350 ℃ and 30.4 mmol·g-1·h-1 at 400 ℃, approximately four and two times higher than that of the commercial fused-iron catalyst (3.4 mmol·g-1·h-1 at 350 ℃ and 16.7 mmol·g-1·h-1 at 400 ℃) under the same condition, respectively. The excellent performance of K-Fe/C can be ascribed to the inherited structure derived from the metal-organic frame precursors and the promotion of potassium, which can modify the binding energy of reactant molecules on the Fe surface, transfer electrons to iron for effective activation of nitrogen, prevent agglomeration of Fe nanoparticle (NPs) and restrain side reaction of carbon matrix to methane.

Research Article Issue
Wet-chemistry synthesis of cobalt carbide nanoparticles as highly active and stable electrocatalyst for hydrogen evolution reaction
Nano Research 2017, 10 (4): 1322-1328
Published: 18 February 2017
Downloads:26

Transition metal carbide (TMC) nanomaterials are promising alternatives to Pt, and are widely used as heterogeneous electrocatalysts for the electrochemical hydrogen evolution reaction (HER). In this work, a bromide-induced wet-chemistry strategy to synthesize Co2C nanoparticles (NPs) was developed. Such NPs exhibited high electrocatalytic activity (η = 181 mV for j = -10 mA·cm-2) and long-term stability (no obvious performance decrease after 4, 000 cycles) for the HER. This study will pave the way for the design and fabrication of TMC NPs via a wet- chemistry method, and will have significant impacts on broader areas such as nanocatalysis and energy conversion.

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