  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.
