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

## TL;DR

This paper introduces a novel hybrid catalyst made from doped MoSe2 nanoflakes and metal oxides, demonstrating high efficiency and stability for hydrogen evolution across all pH levels, advancing sustainable hydrogen production.

## Contribution

It presents a new non-noble metal hybrid catalyst with enhanced activity and stability for pH-universal electrochemical hydrogen evolution, utilizing chlorine-doped MoSe2 nanoflakes and metal oxides.

## Key findings

- Achieved low overpotentials of 0.081V in acid and 0.064V in alkaline conditions at 10mAcm-2.
- Demonstrated high electrochemical stability in both acidic and alkaline electrolytes.
- Developed a facile electrode stacking method for improved HER performance.

## 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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Source: https://tomesphere.com/paper/1903.08947