Regulating the electronic configuration of ruthenium nanoparticles via coupling cobalt phosphide for hydrogen evolution in alkaline media

Xiao, Xin; Wang, Xingsheng; Li, B.; Jiang, Xingxing; Zhang, Y.; Li, M.; Song, Shaowei; Chen, S.; Wang, Minghao; Shen, Yan; Ren, Zhifeng

doi:10.1016/j.mtphys.2020.100182

Cited by 30 publications

(25 citation statements)

References 46 publications

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“…To further rationalize the OER activity of Na x CoO 2 , the charge-transfer resistance and the electrochemical active surface area (ECSA) of each of the samples are shown in Figure S7b and Table , respectively. Although all of the Na x CoO 2 samples exhibit high charge-transfer resistance at the interface, much higher than that of NiFe (oxy)hydroxide, , Na 0.75 CoO 2 displays the lowest charge-transfer resistance among the samples studied, as indicated by the electrochemical impedance spectroscopy curves shown in Figure S7b, which contributes to its low onset potential and competent performance. Na 0.75 CoO 2 also has high bulk electrical conductivity benefiting from its good crystallinity and optimized Na concentration.…”

Section: Resultssupporting

confidence: 77%

Electrochemical Insight into Na_xCoO₂ for the Oxygen Evolution Reaction and the Oxygen Reduction Reaction

et al. 2021

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Layered Na x CoO2 provides multiple degrees of freedom for manipulating its structure and physical properties by tuning the Na concentration, leading to specific functionalities including thermoelectricity, superconductivity, and potentiality in Li-/Na-ion batteries. However, the contribution of varied Na to charge transfer, electrocatalytic kinetics, and energetics in terms of the electrochemical interface reaction for the oxygen evolution reaction (OER) in water splitting and the oxygen reduction reaction (ORR) in fuel cells is not yet fully understood. This work reveals that varied Na concentrations indirectly affect the electrochemical OER or ORR activity by changing the Co–O bond in the constituent CoO6 octahedron of Na x CoO2. Tuning the Na concentration gives rise to the unique evolution of the electronic configuration and subsequently further enhances the Co–O bond’s covalency, which results in promoting the catalytic kinetics of OER and ORR. As the Fermi level descends deeper into the O 2p orbitals with increasing Na extraction, the lattice oxygen becomes active in the proton–electron transfer process, which is reflected in the pH and oxygen-concentration dependence of the OER activity. Based on the characterization of its electrochemical properties, the high electrocatalytic activity of Na0.75CoO2, which exhibits competent OER activity superior to that of IrO2, is rationalized. Meanwhile, intrinsic Na0.75CoO2 reveals a half-wave potential of 0.74VRHE for ORR. The evolution of the structure and the electronic configuration of Na x CoO2 related to its electrochemical properties enables further improved Na x CoO2-based catalysts for efficient electrochemical OER and ORR.

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Section: Resultssupporting

confidence: 77%

Electrochemical Insight into Na_xCoO₂ for the Oxygen Evolution Reaction and the Oxygen Reduction Reaction

et al. 2021

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“…reported that the Ru−H can be regulated using Au as electron donor of Ru sites [42] . The cheap transition metals Co and Ni are widely used catalysts for catalysis applications, [43–52] and their electronegativities are 1.88 and 1.91 respectively. Compared with the electronegativity of 2.20 for Ru, they are potential candidates for regulating the electronic structure of Ru site.…”

Section: Figurementioning

confidence: 99%

Optimizing Hydrogen Binding on Ru Sites with RuCo Alloy Nanosheets for Efficient Alkaline Hydrogen Evolution

et al. 2021

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Ruthenium (Ru)‐based catalysts, with considerable performance and desirable cost, are becoming highly interesting candidates to replace platinum (Pt) in the alkaline hydrogen evolution reaction (HER). The hydrogen binding at Ru sites (Ru−H) is an important factor limiting the HER activity. Herein, density functional theory (DFT) simulations show that the essence of Ru−H binding energy is the strong interaction between the 4normaldz2 orbital of Ru and the 1s orbital of H. The charge transfer between Ru sites and substrates (Co and Ni) causes the appropriate downward shift of the 4normaldz2 ‐band center of Ru, which results in a Gibbs free energy of 0.022 eV for H* in the RuCo system, much lower than the 0.133 eV in the pure Ru system. This theoretical prediction has been experimentally confirmed using RuCo alloy‐nanosheets (RuCo ANSs). They were prepared via a fast co‐precipitation method followed with a mild electrochemical reduction. Structure characterizations reveal that the Ru atoms are embedded into the Co substrate as isolated active sites with a planar symmetric and Z‐direction asymmetric coordination structure, obtaining an optimal 4normaldz2 modulated electronic structure. Hydrogen sensor and temperature program desorption (TPD) tests demonstrate the enhanced Ru−H interactions in RuCo ANSs compared to those in pure Ru nanoparticles. As a result, the RuCo ANSs reach an ultra‐low overpotential of 10 mV at 10 mA cm−2 and a Tafel slope of 20.6 mV dec−1 in 1 M KOH, outperforming that of the commercial Pt/C. This holistic work provides a new insight to promote alkaline HER by optimizing the metal‐H binding energy of active sites.

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“…Energy storage and conversion technologies, such as supercapacitor, battery, and electrolysis have been spotlighted due to their high potential for future global energy policies . Among conversion energy techniques, water splitting for clean hydrogen production with zero-emission of pollution is emerging as the best solution for a promising future hydrogen economy. , The high activation energy of hydrogen evolution reaction (HER) at cathode or oxygen evolution reaction (OER) at anode needs to employ high-efficiency noble metal-based catalysts, such as Pt/C or RuO 2 /IrO 2 . − However, the rare source and expensiveness of these catalysts cannot satisfy practical requirements for industrial hydrogen production. In addition, each aforementioned catalyst can effectively promote only a half-reaction, thus efficiency of overall water splitting can face issues in terms of the complicated manufacturing process and total cost.…”

Section: Introductionmentioning

confidence: 99%

Bifunctional Catalyst Derived from Sulfur-Doped VMoO_x Nanolayer Shelled Co Nanosheets for Efficient Water Splitting

Wang

Tran

Chang

et al. 2021

ACS Appl. Mater. Interfaces

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A novel sulfur-doped vanadium–molybdenum oxide nanolayer shelling over two-dimensional cobalt nanosheets (2D Co@S-VMoO x NSs) was synthesized via a facile approach. The formation of such a unique 2D core@shell structure together with unusual sulfur doping effect increased the electrochemically active surface area and provided excellent electric conductivity, thereby boosting the activities for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). As a result, only low overpotentials of 73 and 274 mV were required to achieve a current response of 10 mA cm–2 toward HER and OER, respectively. Using the 2D Co@S-VMoO x NSs on nickel foam as both cathode and anode electrode, the fabricated electrolyzer showed superior performance with a small cell voltage of 1.55 V at 10 mA cm–2 and excellent stability. These results suggested that the 2D Co@S-VMoO x NSs material might be a potential bifunctional catalyst for green hydrogen production via electrochemical water splitting.

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Regulating the electronic configuration of ruthenium nanoparticles via coupling cobalt phosphide for hydrogen evolution in alkaline media

Cited by 30 publications

References 46 publications

Electrochemical Insight into Na_xCoO₂ for the Oxygen Evolution Reaction and the Oxygen Reduction Reaction

Electrochemical Insight into Na_xCoO₂ for the Oxygen Evolution Reaction and the Oxygen Reduction Reaction

Optimizing Hydrogen Binding on Ru Sites with RuCo Alloy Nanosheets for Efficient Alkaline Hydrogen Evolution

Bifunctional Catalyst Derived from Sulfur-Doped VMoO_x Nanolayer Shelled Co Nanosheets for Efficient Water Splitting

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Regulating the electronic configuration of ruthenium nanoparticles via coupling cobalt phosphide for hydrogen evolution in alkaline media

Cited by 30 publications

References 46 publications

Electrochemical Insight into NaxCoO2 for the Oxygen Evolution Reaction and the Oxygen Reduction Reaction

Electrochemical Insight into NaxCoO2 for the Oxygen Evolution Reaction and the Oxygen Reduction Reaction

Optimizing Hydrogen Binding on Ru Sites with RuCo Alloy Nanosheets for Efficient Alkaline Hydrogen Evolution

Bifunctional Catalyst Derived from Sulfur-Doped VMoOx Nanolayer Shelled Co Nanosheets for Efficient Water Splitting

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Electrochemical Insight into Na_xCoO₂ for the Oxygen Evolution Reaction and the Oxygen Reduction Reaction

Electrochemical Insight into Na_xCoO₂ for the Oxygen Evolution Reaction and the Oxygen Reduction Reaction

Bifunctional Catalyst Derived from Sulfur-Doped VMoO_x Nanolayer Shelled Co Nanosheets for Efficient Water Splitting