Role of anionic vacancy for active hydrogen evolution in WTe2

Kwon, Hagyeong; Ji, Byungdo; Bae, Dongyeon; Lee, J. H.; Park, Hee Jung; Kim, Do Hyun; Kim, Young Min; Son, Young Kap; Yang, Heejun; Cho, Suyeon

doi:10.1016/j.apsusc.2020.145972

Cited by 40 publications

(16 citation statements)

References 34 publications

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“…The onset potential (at 10 mA/cm –2 ) of WSe 2 is −0.53 V, in an excellent agreement with an experimental result of −0.51 V . The onset potential of WTe 2 is −0.51 V, which is close to the experiment result, −0.57 V . The relevant physical quantities at the onset potential, such as differential capacitance and the potential of zero charge, are in the Supporting Information.…”

Section: Resultssupporting

confidence: 85%

“…In this paper, we turn our attention to the single-layer MX 2 basal plane, where we expect that the basal plane will provide an abundant number of active sites. It was shown that sulfur vacancies in MoS 2 created under electrochemical conditions are responsible for the high HER reactivity. − However, the interpretation of the role of vacant sites on the basal plane is difficult because the observed reactivity could also be caused by the presence of edge sites. We previously addressed this issue using GCP-K and found that the predicted onset potential and Tafel slope for sulfur vacant sites in the basal plane of 2H MoS 2 agree well with the experiments for both acidic and basic conditions …”

Section: Introductionmentioning

confidence: 99%

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Reaction Mechanism and Strategy for Optimizing the Hydrogen Evolution Reaction on Single-Layer 1T′ WSe₂ and WTe₂ Based on Grand Canonical Potential Kinetics

Song

Kwon

Hossain

et al. 2021

ACS Appl. Mater. Interfaces

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Transition-metal dichalcogenides (TMDs) in the 1T′ phase are known high-performance catalysts for hydrogen evolution reaction (HER). Many experimental and some theoretical studies report that vacant sites play an important role in the HER on the basal plane. To provide benchmark calculations for comparison directly with future experiments on TMDs to obtain a validated detailed understanding that can be used to optimize the performance and material, we apply a recently developed grand canonical potential kinetics (GCP-K) formulation to predict the HER at vacant sites on the basal plane of the 1T′ structure of WSe2 and WTe2. The accuracy of GCP-K has recently been validated for single-crystal nanoparticles. Using the GCP-K formulation, we find that the transition-state structures and the concentrations of the four intermediates (0–3 H at the selenium or tellurium vacancy) change continuously as a function of the applied potential. The onset potential (at 10 mA/cm–2) is −0.53 V for WSe2 (experiment is −0.51 V) and −0.51 V for WTe2 (experiment is −0.57 V). We find multistep reaction mechanisms for H2 evolution from Volmer–Volmer–Tafel (VVT) to Volmer–Heyrovsky (VH) depending on the applied potential, leading to an unusual non-monotonic change in current density with the applied potential. For example, our detailed understanding of the reaction mechanism suggests a strategy to improve the catalytic performance significantly by alternating the applied potential periodically.

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Section: Resultssupporting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Reaction Mechanism and Strategy for Optimizing the Hydrogen Evolution Reaction on Single-Layer 1T′ WSe₂ and WTe₂ Based on Grand Canonical Potential Kinetics

Song

Kwon

Hossain

et al. 2021

ACS Appl. Mater. Interfaces

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“…The value is significantly larger than that of the Ag film, 0.076 cm 2 (Figure S11), and pristine WTe 2 , 0.03 mF/cm. 39 Consistent with the SEM images (Figure 1c,d) and electrochemical active surface area (ECSA) analysis (Figure 4e), our nanoporous AgTe realizes a large electrochemically active surface area, leading to the excellent HER catalytic activity.…”

Section: Resultssupporting

confidence: 83%

“…The C DL of the nanoporous AgTe was estimated to be 35.6 mF/cm 2 , deduced from the linear fitting of the current density as a function of the scan rate, as shown in Figure e. The value is significantly larger than that of the Ag film, 0.076 cm 2 (Figure S11), and pristine WTe 2 , 0.03 mF/cm . Consistent with the SEM images (Figure c,d) and electrochemical active surface area (ECSA) analysis (Figure e), our nanoporous AgTe realizes a large electrochemically active surface area, leading to the excellent HER catalytic activity.…”

Section: Resultssupporting

confidence: 75%

Nanoporous Silver Telluride for Active Hydrogen Evolution

et al. 2021

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Silver-based nanomaterials have been versatile building blocks of various photoassisted energy applications; however, they have demonstrated poor electrochemical catalytic performance and stability, in particular, in acidic environments. Here we report a stable and high-performance electrochemical catalyst of silver telluride (AgTe) for the hydrogen evolution reaction (HER), which was synthesized with a nanoporous structure by an electrochemical synthesis method. X-ray spectroscopy techniques on the nanometer scale and high-resolution transmission electron microscopy revealed an orthorhombic structure of nanoporous AgTe with precise lattice constants. First-principles calculations show that the AgTe surface possesses highly active catalytic sites for the HER with an optimized Gibbs free energy change of hydrogen adsorption (−0.005 eV). Our nanoporous AgTe demonstrates exceptional stability and performance for the HER, an overpotential of 27 mV, and a Tafel slope of 33 mV/dec. As a stable catalyst for hydrogen production, AgTe is comparable to platinum-based catalysts and provides a breakthrough for high-performance electrochemical catalysts.

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“…Additionally, WTe 2 has been touted as a promising candidate for large-gap quantum spin Hall insulators [5,21,22]. Lastly, through electrochemical investigations, the possibility of using WTe 2 as a catalyst for the hydrogen evolution reaction (HER) has been examined [24,[27][28][29][30].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of tungsten ditelluride thin films and highly crystalline nanobelts from pre-deposited reactants

et al. 2020

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Tungsten ditelluride (WTe 2) is a layered transition metal dichalcogenide (TMD) that has attracted increasing research interest in recent years. WTe 2 has demonstrated large non-saturating magnetoresistance, potential for spintronic applications and promise as a type-II Weyl semimetal. The majority of works on WTe 2 have relied on mechanically exfoliated flakes from chemical vapour transport (CVT)-grown crystals for their investigations. While producing high-quality samples, this method is hindered by several disadvantages including long synthesis time, high-temperature annealing and an inherent lack of scalability. In this work, a synthesis method is demonstrated that allows the production of large-area polycrystalline films of WTe 2. This is achieved by the reaction of pre-deposited films of W and Te at a relatively low temperature of 550 °C. Sputter X-ray photoelectron spectroscopy reveals the rapid but self-limiting nature of the oxidation of these WTe 2 films in ambient conditions. The WTe 2 films are composed of areas of micrometre-sized nanobelts that can be isolated and offer potential as an alternative to CVT-grown samples. These nanobelts are highly crystalline with low defect densities indicated by transmission electron microscopy and show promising initial electrical results.

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Role of anionic vacancy for active hydrogen evolution in WTe2

Cited by 40 publications

References 34 publications

Reaction Mechanism and Strategy for Optimizing the Hydrogen Evolution Reaction on Single-Layer 1T′ WSe₂ and WTe₂ Based on Grand Canonical Potential Kinetics

Reaction Mechanism and Strategy for Optimizing the Hydrogen Evolution Reaction on Single-Layer 1T′ WSe₂ and WTe₂ Based on Grand Canonical Potential Kinetics

Nanoporous Silver Telluride for Active Hydrogen Evolution

Synthesis of tungsten ditelluride thin films and highly crystalline nanobelts from pre-deposited reactants

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Role of anionic vacancy for active hydrogen evolution in WTe2

Cited by 40 publications

References 34 publications

Reaction Mechanism and Strategy for Optimizing the Hydrogen Evolution Reaction on Single-Layer 1T′ WSe2 and WTe2 Based on Grand Canonical Potential Kinetics

Reaction Mechanism and Strategy for Optimizing the Hydrogen Evolution Reaction on Single-Layer 1T′ WSe2 and WTe2 Based on Grand Canonical Potential Kinetics

Nanoporous Silver Telluride for Active Hydrogen Evolution

Synthesis of tungsten ditelluride thin films and highly crystalline nanobelts from pre-deposited reactants

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Product

Resources

About

Reaction Mechanism and Strategy for Optimizing the Hydrogen Evolution Reaction on Single-Layer 1T′ WSe₂ and WTe₂ Based on Grand Canonical Potential Kinetics

Reaction Mechanism and Strategy for Optimizing the Hydrogen Evolution Reaction on Single-Layer 1T′ WSe₂ and WTe₂ Based on Grand Canonical Potential Kinetics