Electrocatalytic water splitting to hydrogen (H2) is
an ideal approach to generate renewable energy. One of the major drawbacks
is the tightly coupled kinetically sluggish and energy inefficient
anodic oxygen evolution reaction (OER) with hydrogen forming a cathodic
half-cell reaction which leads to a significant reduction in overall
cell efficiency. In this context, before reviewing the literature,
we have first briefly analyzed the energetics of overall water splitting,
problems, and challenges under different pH conditions which can be
useful for the further understanding of the process. Replacement of
the anodic OER by a thermodynamically favorable substrate oxidation
offers flexibility, value addition, and energy efficiency in the case
of hybrid or assisted water electrolysis to afford hydrogen. Recent
progress in terms of sacrificial oxidants in hybrid water electrolysis
are discussed in this context, where the sacrificial oxidants are
so chosen that the oxidation often leads to its value addition. Also
here, we have offered insights into interface designing in heterostructures
by modulating chemical and electronic environments for the enhancement
of the intrinsic catalytic activity and stability. The effect of incorporation
of such materials into the overall water splitting reaction, their
catalytic active sites, and interactions with intermediates are thoroughly
explored. This review can be a good complement for better understanding
of the elucidation of the interface role in hybrid water electrolysis
for future commercial applications.