  The formation and disassociation of excitons plays a crucial role in any
photovoltaic or photocatalytic application. However, excitonic effects are
seldom considered in materials discovery studies due to the monumental
computational cost associated with the examination of these properties. Here,
we study the excitonic properties of nearly 50 photocatalysts using
state-of-the-art Bethe-Salpeter formalism. These $\sim$ 50 materials were
recently recognized as promising photocatalysts for CO$_2$ reduction through a
data-driven screening of 68,860 materials. Here, we propose three screening
criteria based on the optical properties of these materials, taking excitonic
effects into account, to further down select 6 materials. Remarkably we find a
strong correlation between the exciton binding energies obtained from the
Bethe-Salpeter formalism and those obtained from the computationally much
less-expensive Wannier-Mott model for these chemically diverse $\sim$ 50
materials. This work presents a new paradigm towards the inclusion of excitonic
effects in future materials discovery for solar-energy harvesting applications.
