Chapter 4
Hydrogen Evolution from
Two-Dimensional Materials
4.1 Introduction
Storage of energy in the form of chemical bonds is one of the most used and
efficient way of storing the energy. Transferring energy from one place to other
in form of chemical bonds is easier as compared to the other means such as
electricity. On the other hand, the deteriorating environmental conditions due
to the excess burning of the petroleum fuels needs our attention to look for
the alternative forms of chemical energy not having deleterious effect on the
environment. One such fuel is hydrogen which can be used in the fuel cells thus
involving no emission of greenhouse gas whatsoever 40, 41. However, a cheap
and efficient way of producing hydrogen has not been realized yet 42, 43, 44.
One of the bottleneck to reduce the cost of hydrogen production is the use of
expensive catalysts like Platinum a cheaper and efficient alternative of which
has not been found yet. Recent theoretical and experimental investigations of
the bulk Ni2P for hydrogen evolution reaction (HER) show promising results
and hopefully in the future will serve as a viable alternative to Platinum for
the HER 45, 46, 47.
Additionally, over the last few years, two-dimensional (2D) MoS2 has been
explored for its activity towards the HER with some promising results 48,
49, 50, 51, 52. The initial effort of the MoS2 research was focussed on the
edges of the 2H structure of the MoS2 nanoparticle having metallic character
as opposed to the semiconducting states on the basal plane 53, 54. Unfor-
25