Two‐Dimensional Porous Molybdenum Phosphide/Nitride Heterojunction Nanosheets for pH‐Universal Hydrogen Evolution Reaction

Angewandte Chemie International Edition, Journal Year: 2020, Volume and Issue: 60(12), P. 6673 - 6681

Published: Dec. 18, 2020

Abstract Herein, we present a new strategy for the synthesis of 2D porous MoP/Mo 2 N heterojunction nanosheets based on pyrolysis [PMo 12 O 40 ] 3− ‐melamine (PMo ‐MA) nanosheet precursor from polyethylene glycol (PEG)‐mediated assembly route. The heterostructure are ca. 20 nm thick and have plentiful pores (<5 nm). These structure features offer advantages to promote HER activity, including favorable water dissociation kinetics around as confirmed by theoretical calculations, large accessible surface nanosheets, enhanced mass‐transport ability pores. Consequently, exhibit excellent activity with low overpotentials 89, 91 89 mV achieve current density 10 mA cm −2 in alkaline, neutral acidic electrolytes, respectively. performance is superior commercial Pt/C at >55 medium >190 alkaline medium.

Language: Английский

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Reversed Charge Transfer and Enhanced Hydrogen Spillover in Platinum Nanoclusters Anchored on Titanium Oxide with Rich Oxygen Vacancies Boost Hydrogen Evolution Reaction

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(30), P. 16622 - 16627

Published: May 18, 2021

Abstract The catalytic activity of metal clusters is closely related with the support; however, knowledge on influence support scarce. We demonstrate that Pt nanoclusters (NCs) anchored porous TiO 2 nanosheets rich oxygen vacancies ( V O ‐rich Pt/TiO ) and deficient ‐deficient ), display significantly different for hydrogen evolution reaction (HER), in which shows a mass 45.28 A mg −1 at −0.1 vs. RHE, 16.7 58.8 times higher than those commercial Pt/C, respectively. DFT calculations situ Raman spectra suggest can simultaneously achieve reversed charge transfer (electrons from to NCs) enhanced spillover NCs support, leads electron‐rich being amenable proton reduction absorbed H*, as well acceleration desorption sites—both promoting HER. Our work provides new strategy rational design highly efficient HER catalysts.

Language: Английский

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Rational Design of Single‐Atom Site Electrocatalysts: From Theoretical Understandings to Practical Applications

Advanced Materials, Journal Year: 2021, Volume and Issue: 33(34)

Published: July 8, 2021

Atomically dispersed metal-based electrocatalysts have attracted increasing attention due to their nearly 100% atomic utilization and excellent catalytic performance. However, current fundamental comprehension summaries reveal the underlying relationship between single-atom site (SACs) corresponding application are rarely reported. Herein, understandings intrinsic mechanisms SACs electrocatalytic applications systemically summarized. Different preparation strategies presented synthetic with engineering well-defined on basis of theoretical principle (size effect, metal-support interactions, electronic structure coordination environment effect). Then, an overview is presented, including oxygen reduction reaction, hydrogen evolution oxidation small organic molecules, carbon dioxide nitrogen reaction. The structure-performance reactions also discussed in depth expound enhancement mechanisms. Finally, a summary provided perspective supplied demonstrate challenges opportunities for rational designing, synthesizing, modulating advanced toward reactions.

Language: Английский

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Conductive Metal–Organic Frameworks with Extra Metallic Sites as an Efficient Electrocatalyst for the Hydrogen Evolution Reaction

Advanced Science, Journal Year: 2020, Volume and Issue: 7(9)

Published: March 16, 2020

Abstract The 2D conductive metal–organic frameworks (MOFs) are expected to be an ideal electrocatalyst due their high utilization of metal atoms. Exploring a new conjugated ligand with extra active metallic center can further boost the structural advantages MOFs. In this work, hexaiminohexaazatrinaphthalene (HAHATN) is employed as construct bimetallic sited MOFs (M2 3 (M1 ∙HAHATN) 2 ) M–N moiety. Density functional theory (DFT) calculations demonstrate that framework renders M2 electric conductivity narrow bandgap (0.19 eV) for electron transfer and favorable in‐plane porous structure (2.7 nm) mass transfer. Moreover, atom at moiety has higher unsaturation degree than 4 linkage, resulting in stronger ability donate electrons enhancing electroactivity. These characteristics endow enhanced electroactivity hydrogen evolution reaction (HER) electrocatalysis. Among series MOF, Ni (Ni nanosheets optimal exhibit small overpotential 115 mV 10 mA cm −2 , low Tafel slope (45.6 dec −1 ), promising electrocatalytic stability HER. This work provides effective strategy designing

Language: Английский

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A durable and pH-universal self-standing MoC–Mo2C heterojunction electrode for efficient hydrogen evolution reaction

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: Nov. 22, 2021

Efficient water electrolyzers are constrained by the lack of low-cost and earth-abundant hydrogen evolution reaction (HER) catalysts that can operate at industry-level conditions be prepared with a facile process. Here we report self-standing MoC-Mo2C catalytic electrode via one-step electro-carbiding approach using CO2 as feedstock. The outstanding HER performances low overpotentials 500 mA cm-2 in both acidic (256 mV) alkaline electrolytes (292 mV), long-lasting lifetime over 2400 h (100 d), high-temperature performance (70 oC) due to hydrophilic porous surface, intrinsic mechanical strength self-grown MoC (001)-Mo2C (101) heterojunctions have ΔGH* value -0.13 eV condition, energy barrier 1.15 for dissociation solution. preparation large (3 cm × 11.5 cm) demonstrates possibility scaling up this process prepare various carbide electrodes rationally designed structures, tunable compositions, favorable properties.

Language: Английский

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