Fine-tuning interlayer spacing in MoS2 for enriching 1T phase via alkylated ammonium ions for electrocatalytic hydrogen evolution reaction

Venkateshwaran, Selvaraj; Josline, Mukkath Joseph; Kumar, Sakkarapalayam Murugesan Senthil

doi:10.1016/j.ijhydene.2020.12.054

Cited by 25 publications

(18 citation statements)

References 51 publications

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“…Figure 2a shows the Mo 3d region of the as-prepared MoS 2 , which means that the material is analyzed before the process of solvothermal agitation, where the peaks of Mo 3d 3/2 and Mo 3d 5/2 that appeared at the binding energy values of 232.3 and 229.1 eV, respectively, revealed that the material is in the pure 2H phase. 17,27 In the XPS spectrum of 2H-MoS 2 -H 2 O, 2H-MoS 2 -EtOH, and 2H-MoS 2 -DMF samples (shown in Figure 2b−d, respectively), Mo 3d 3/2 and Mo 3d 5/2 peaks appeared at binding energy values of ∼231.4 and ∼228.2 eV, respectively, which are nearly 1.0 eV lower than the corresponding peaks of 2H phase MoS 2 . The appearance of the 1T phase at lower binding energy in the XPS spectrum is mainly due to their metastable nature and octahedral coordination, where the relaxation energy is ∼1.0 eV lower than the thermodynamically stable and trigonal prismatically coordinated 2H phase MoS 2 .…”

Section: ■ Results and Discussionmentioning

confidence: 95%

“…The obtained results are consistent with our previous report and strongly evident in the formation of highly pure 2H phase MoS 2 . 17,27 The Phase Conversion of Semiconducting 2H-MoS 2 to Metallic 1T-MoS 2 . After confirming the material nature and phase purity of 2H-MoS 2 , it is subjected to phase conversion through the solvothermal agitation process by employing four distinctly varied solvents such as water, ethanol, DMF, and benzene.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…21,26 Moreover, in contrast to the Li + ion intercalation technique, in the solvothermal agitation route, the circumstances of high temperature and pressure assist in the intercalation of solvent molecules, weakening the van der Waals force of attraction between the layers of MoS 2 and accelerating the kinetics of phase conversion. 17,27 However, the area of solvothermal agitation of 2H-MoS 2 is an upgrowing zone and has not yet been explored well. A recent study demonstrated the solvothermal agitation of 2H-MoS 2 with ethanol solvent, and the obtained 1T-MoS 2 material was employed as an electrocatalyst in HER.…”

Section: ■ Introductionmentioning

confidence: 99%

“…The alternative approach to replace the Li + ion intercalation route of phase conversion is solvothermal agitation, where the prepared 2H-MoS 2 is allowed for phase transformation from a thermodynamically stable phase to a metastable phase, which is stabilized by the intercalated solvent molecules. The intercalated solvent molecules enhance the interlayer space that reinforces the activity of 1T-MoS 2 in HER by lowering the hydrogen adsorption free energy. , Moreover, in contrast to the Li + ion intercalation technique, in the solvothermal agitation route, the circumstances of high temperature and pressure assist in the intercalation of solvent molecules, weakening the van der Waals force of attraction between the layers of MoS 2 and accelerating the kinetics of phase conversion. , However, the area of solvothermal agitation of 2H-MoS 2 is an upgrowing zone and has not yet been explored well. A recent study demonstrated the solvothermal agitation of 2H-MoS 2 with ethanol solvent, and the obtained 1T-MoS 2 material was employed as an electrocatalyst in HER .…”

Section: Introductionmentioning

confidence: 99%

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Provoking Metallic 1T Phase Conversion of 2H-MoS₂ via an Effectual Solvothermal Route for Electrocatalytic Water Reduction in Acid

Venkateshwaran

Kumar

2022

ACS Sustainable Chem. Eng.

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Recently, the exploration of MoS 2 -based catalysts especially with a metallic 1T phase has gained immense attention due to their improvised electrocatalytic performance in hydrogen evolution reaction (HER). The dominance in electrical conductivity, hydrophilicity, and density of active sites with the metallic 1T phase over a semiconducting 2H phase is liable for their promoted catalytic performance. The direct formation of MoS 2 with an electrocatalytically active 1T phase is hard to attain and demands a proficient method since it is a metastable phase, whereas the 2H phase is a thermodynamically stable and predominantly formed phase in MoS 2 . On the other hand, in MoS 2 , the phase conversion from the thermodynamically stable 2H phase to the metastable 1T phase can be feasible with the Li + ion exfoliation technique. Although it is the foremost employed technique for the industrial-scale formation of 1T-MoS 2 at present, the tedious and sedate intercalation/exfoliation process and the usage of explosive Li metal are the prime drawbacks within it. To overcome these issues, in this report, we have proposed a new route for the facile conversion of the 2H phase to the metallic 1T phase in MoS 2 , which is a solvothermal agitation process with N,N-dimethylformamide (DMF) solvent, where the interlayer expansion due to the intercalation of DMF was observed, which assisted in the attainment of maximal (78.6%) conversion of the 1T phase. Then, the electrocatalytic performance of the prepared 1T-MoS 2 catalysts in HER was tested and they showed tremendous activity. To attain a current density of 10 mA cm −2 , it demanded 262 mV with a lower Tafel slope value of 53 mV/dec. This humble expedient technique can be valid to the other 2D materials for the facile conversion of the 2H phase to the electrochemically active 1T phase.

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Section: ■ Results and Discussionmentioning

confidence: 95%

Section: ■ Results and Discussionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Provoking Metallic 1T Phase Conversion of 2H-MoS₂ via an Effectual Solvothermal Route for Electrocatalytic Water Reduction in Acid

Venkateshwaran

Kumar

2022

ACS Sustainable Chem. Eng.

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“…(b) the multi-potential steps and (c) the multi-current steps; Figure S11: The comparison of the corresponding overpotentials at 10 mA cm −2 and 50 mA cm −2 current outputs based on different deposition time electrodes; Figure S12: The comparison of the corresponding overpotentials at 10 mA cm −2 and 50 mA cm −2 current outputs based on different doping concentrations electrodes; Figure S13: The high-resolution (a) Co 2p and (b) Fe 2p spectra of CoFe LDH electrode and CoFe LDH powder; Table S1: Summary of parameters for sample preparation; Table S2: Comparison of the HER performance of CoFeCr LDH catalyst with other reported OER catalysts. References [ 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ] are cited in the Supplementary Materials.…”

mentioning

confidence: 99%

Chromium-Modified Ultrathin CoFe LDH as High-Efficiency Electrode for Hydrogen Evolution Reaction

Zhang

et al. 2022

Nanomaterials

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Hydrogen evolution reaction (HER) has a dominant function in energy conversion and storage because it supplies a most effective way for converting electricity into sustainable high-purity hydrogen. Layered double hydroxides (LDHs) have shown promising performance in the process of electrochemical water oxidation (a half-reaction for water splitting). Nevertheless, HER properties have not been well released due to the structural characteristics of related materials. Herein, a simple and scalable tactics is developed to synthesize chromium-doped CoFe LDH (CoFeCr LDH). Thanks to oxygen vacancy, optimized electronic structure and interconnected array hierarchical structure, our developed ternary CoFeCr-based layered double hydroxide catalysts can provide 10 mA cm−2 current density at −0.201 V vs. RHE with superior long-term stability in alkaline electrolyte. We anticipate that the simple but feasible polymetallic electronic modulation strategy can strengthen the electrocatalytic property of the layered double hydroxides established in the present study, based on a carbon neutral and hydrogen economy.

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Uniform Synthesis of Bilayer Hydrogen Substituted Graphdiyne for Flexible Piezoresistive Applications

Josline,

Ghods,

Kosame

et al. 2024

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Graphdiyne (GDY) has garnered significant attention as a cutting‐edge 2D material owing to its distinctive electronic, optoelectronic, and mechanical properties, including high mobility, direct bandgap, and remarkable flexibility. One of the key challenges hindering the implementation of this material in flexible applications is its large area and uniform synthesis. The facile growth of centimeter‐scale bilayer hydrogen substituted graphdiyne (Bi‐HsGDY) on germanium (Ge) substrate is achieved using a low‐temperature chemical vapor deposition (CVD) method. This material's field effect transistors (FET) showcase a high carrier mobility of 52.6 cm2 V−1 s−1 and an exceptionally low contact resistance of 10 Ω µm. By transferring the as‐grown Bi‐HsGDY onto a flexible substrate, a long‐distance piezoresistive strain sensor is demonstrated, which exhibits a remarkable gauge factor of 43.34 with a fast response time of ≈275 ms. As a proof of concept, communication by means of Morse code is implemented using a Bi‐HsGDY strain sensor. It is believed that these results are anticipated to open new horizons in realizing Bi‐HsGDY for innovative flexible device applications.

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Fine-tuning interlayer spacing in MoS2 for enriching 1T phase via alkylated ammonium ions for electrocatalytic hydrogen evolution reaction

Cited by 25 publications

References 51 publications

Provoking Metallic 1T Phase Conversion of 2H-MoS₂ via an Effectual Solvothermal Route for Electrocatalytic Water Reduction in Acid

Provoking Metallic 1T Phase Conversion of 2H-MoS₂ via an Effectual Solvothermal Route for Electrocatalytic Water Reduction in Acid

Chromium-Modified Ultrathin CoFe LDH as High-Efficiency Electrode for Hydrogen Evolution Reaction

Uniform Synthesis of Bilayer Hydrogen Substituted Graphdiyne for Flexible Piezoresistive Applications

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Fine-tuning interlayer spacing in MoS2 for enriching 1T phase via alkylated ammonium ions for electrocatalytic hydrogen evolution reaction

Cited by 25 publications

References 51 publications

Provoking Metallic 1T Phase Conversion of 2H-MoS2 via an Effectual Solvothermal Route for Electrocatalytic Water Reduction in Acid

Provoking Metallic 1T Phase Conversion of 2H-MoS2 via an Effectual Solvothermal Route for Electrocatalytic Water Reduction in Acid

Chromium-Modified Ultrathin CoFe LDH as High-Efficiency Electrode for Hydrogen Evolution Reaction

Uniform Synthesis of Bilayer Hydrogen Substituted Graphdiyne for Flexible Piezoresistive Applications

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Provoking Metallic 1T Phase Conversion of 2H-MoS₂ via an Effectual Solvothermal Route for Electrocatalytic Water Reduction in Acid

Provoking Metallic 1T Phase Conversion of 2H-MoS₂ via an Effectual Solvothermal Route for Electrocatalytic Water Reduction in Acid