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Open Access Research Article Issue
Synthesis of Co, Ni-doped MoS2 as durable and pH-universal catalyst for hydrogen evolution
Energy Materials and Devices 2023, 1 (2): 9370024
Published: 29 January 2024
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Molybdenum disulfide (MoS2) has garnered significant attention as a potential substitute for Pt catalysts in the hydrogen evolution reaction (HER). Furthermore, there is a need to explore cost-effective and efficient electrocatalysts that can perform well across different pH levels. In this study, a straightforward hydrothermal method is presented to synthesize Ni, Co-doped MoS2 nanosheets on carbon fiber paper (Ni, Co-MoS2/CFP) for HER in various pH environments. The findings suggest that strategic doping not only alters the structure and composition of Ni, Co-MoS2/CFP but also enhances its inherent electrocatalytic activity while facilitating the transformation of the MoS2 phase. The overpotentials observed for Ni, Co-MoS2/CFP are 95.6, 154, and 144 mV (at 10 mA cm−2) under alkaline, acidic, and neutral environments respectively. The exceptional performance of Ni, Co-MoS2/CFP in HER can be attributed to the introduction of nickel and cobalt dopants which increase porosity and expose more active sites. This one-step doping technique presents a novel approach to modulating catalytic activity across all pH ranges.

Research Article Issue
Intrinsic-trap-regulating growth of clean graphene on high-entropy alloy substrate
Nano Research 2022, 15 (5): 4717-4723
Published: 27 January 2022
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A facile way to grow few-layer graphene on high-entropy alloy sheets is presented in this work. We systematically investigate the growth mechanism of graphene using the unique properties of FeCoNiCu0.25 high-entropy alloys. The intrinsic-trap-regulating growth mechanism derives from the synergistic effect of the multi-metal atoms and sluggish diffusion of high-entropy alloy. As a result, as-obtained few-layer of graphene has the characteristics of wide coverage, large size, good continuity, and high crystallinity with less amorphous carbon and extra wrinkles. Factors such as the Cu content, annealing time, growth temperature, growth time, carbon source flow rate, hydrogen flow rate and heat treatment method play a key role in the growth of high-quality graphene, and the best growth parameters have been explored. Besides, increasing alloy entropy is found to be responsible for the formation of high-quality graphene.

Open Access Issue
Facile and secure synthesis of porous partially fluorinated graphene employing weakly coordinating anion for enhanced high-performance symmetric supercapacitor
Journal of Materiomics 2022, 8 (1): 113-122
Published: 18 May 2021
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In this paper, porous partially fluorinated graphene (PFG) for supercapacitors (SCs) was fabricated by a mild and secure one-pot hydrothermal method utilizing weakly coordinating anion BF4 as the fluorine source. The hydrolysis rate of sodium fluoroborate was adjusted by controlling the reaction temperature and PFG containing semi-ionic C-F bonds was obtained, where the content of semi-ionic C-F bonds in PFG can be easily regulated. The final experimental results show that the incorporation of fluorine not only modulates the electrochemical properties of the material, but also creates abundant pores. When assembled in a symmetric supercapacitor, the PFG shows a high specific capacitance of 269.7 F g−1 at 1 A g−1 and a superior rate capability with 89.3% capacitance retained, as the current density is increased from 1 A g−1 even to 20 A g−1. Furthermore, the resultant energy density for PFG is 9.4 Wh kg−1 at a power density of 250.0 W kg−1 (1 A g−1). All these results confirm that as-prepared partially fluorinated graphene is appropriate for the application in SCs and mass production.

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