Catalysts for the hydrogen evolution reaction in alkaline medium: Configuring a cooperative mechanism at the Ag-Ag$_2$S-MoS$_2$ interface

Autor: Avraham Bar-Hen, Simon Hettler, Ashwin Ramasubramaniam, Raul Arenal, Ronen Bar-Ziv, Maya Bar Sadan
Přispěvatelé: United States-Israel Binational Science Foundation, National Science Foundation (US), Israel Atomic Energy Commission, Pazy foundation, European Commission, Agencia Estatal de Investigación (España), Ministerio de Ciencia, Innovación y Universidades (España)
Rok vydání: 2022
Předmět:
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
instname
Journal of Energy Chemistry
DOI: 10.48550/arxiv.2209.04557
Popis: Designing electrocatalysts for HER in alkaline conditions to overcome the sluggish kinetics associated with the additional water dissociation step is a recognized challenge in promoting the hydrogen economy. To this end, delicately tuning the atomic-scale structure and surface composition of nanoparticles is a common strategy and, specifically, making use of hybrid structures, can produce synergistic effects that lead to highly active catalysts. Here, we present a core-shell catalyst of Ag@MoS2 that shows promising results towards the hydrogen evolution reaction (HER) in both 0.5 M H2SO4 and 0.5 M KOH. In this hybrid structure, the MoS2 shell is strained and defective, and charge transfer occurs between the conductive core and the shell, contributing to the electrocatalytic activity. The shelling process results in a large fraction of Ag2S in the cores, and adjusting the relative fractions of Ag, Ag2S, and MoS2 leads to improved catalytic activity and fast charge-transfer kinetics. We suggest that the enhancement of alkaline HER is associated with a cooperative effect of the interfaces, where the Ag(I) sites in Ag2S drive the water dissociation step, and the formed hydrogen subsequently recombines on the defective MoS2 shell. This study demonstrates the benefits of hybrid structures as functional nanomaterials and provides a scheme to activate MoS2 for HER in alkaline conditions.
This research was supported by the United States-Israel Binational Science Foundation (BSF), Jerusalem, Israel and the United States National Science Foundation (NSF) grant 2017642, and partly from the Israeli Atomic Energy Commission–Prof. A. Pazy joint foundation, ID126-2020. S.H. and R.A. acknowledge funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 889546 as well as from the Spanish MICINN (project grant PID2019-104739GB-100/AEI/10.13039/501100011033). R.A. also support the funding from the European Union H2020 program Graphene Flagship CORE3 (881603).
Databáze: OpenAIRE
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