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arXiv · 1903.08947

Doped-MoSe2 nanoflakes/3d metal oxide-hydr(oxy)oxides hybrid catalysts for pH-universal electrochemical hydrogen evolution reaction

Leyla Najafi·Sebastiano Bellani·Reinier Oropesa-Nuñez·Alberto Ansaldo·Mirko Prato·Antonio Esau Del Rio Castillo·Francesco Bonaccorso
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Abstract

Clean hydrogen production through efficient and cost-effective electrochemical water splitting is highly promising to meeting future global energy demands. The design of Earth-abundant materials with both high activity for hydrogen evolution reaction (HER) and electrochemical stability in both acidic and alkaline environments summarize the outcomes needed for practical applications. Here, we report a non-noble 3d metal Cl-chemical doping of liquid phase exfoliated single/few-layer flakes of MoSe2 for creating MoSe2 nanoflakes/3d metal oxide-hydr(oxy)oxide hybrid HER-catalysts. We propose that the electron-transfer from MoSe2 nanoflakes to metal cations and the chlorine complexation-induced both neutralization, as well as the in situ formation of metal oxide-hydr(oxy)oxides on MoSe2 nanoflake's surface, tailor the proton affinity of the derived catalysts, increasing the number and HER-kinetic of their active sites in both acidic and alkaline electrolytes. The electrochemical coupling between the doped-MoSe2 nanoflakes/metal oxide-hydr(oxy)oxide hybrids and single-walled carbon nanotubes heterostructures further accelerates the HER process. Lastly, monolithic stacking of multiple heterostructures is reported as a facile electrode assembly strategy to achieve overpotential for a cathodic current density of 10mAcm-2 of 0.081V and 0.064V in 0.5M H2SO4 and 1M KOH, respectively. This opens up new opportunities to address the current density vs. overpotential requirements targeted in pH-universal H2 production.

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Leyla Najafi, Sebastiano Bellani, Reinier Oropesa-Nuñez, Alberto Ansaldo, Mirko Prato, Antonio Esau Del Rio Castillo, Francesco Bonaccorso. 2019-03-21. Doped-MoSe2 nanoflakes/3d metal oxide-hydr(oxy)oxides hybrid catalysts for pH-universal electrochemical hydrogen evolution reaction. https://doi.org/10.1002/aenm.201801764

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