Green production
of hydrogen is possible with photocatalytic water
splitting, where hydrogen is produced while water is reduced by using
energy derived from light. In this study, density functional theory
(DFT) is employed to gain insights into the photocatalytic performance
of La
5
Ti
2
AgS
5
O
7
and La
5
Ti
2
CuS
5
O
7
—two emerging
candidate materials for water splitting. The electronic structure
of both bulk materials was calculated by using hybrid DFT, which indicated
the band gaps and charge carrier effective masses are suitable for
photocatalytic water splitting. Notably, the unique one-dimensional
octahedral TiO
x
S
6–
x
and tetragonal MS
4
channels formed provide
a structural separation for photoexcited charge carriers which should
inhibit charge recombination. Band alignments of surfaces that appear
on the Wulff constructions of 12 nonpolar symmetric surface slabs
were calculated by using hybrid DFT for each of the materials. All
surfaces of La
5
Ti
2
AgS
5
O
7
have band edge positions suitable for hydrogen evolution; however,
the small overpotentials on the largest facets likely decrease the
photocatalytic activity. In La
5
Ti
2
CuS
5
O
7
, 72% of the surface area can support oxygen evolution
thermodynamically and kinetically. Based on their similar electronic
structures, La
5
Ti
2
AgS
5
O
7
and La
5
Ti
2
CuS
5
O
7
could
be effectively employed in Z-scheme photocatalytic water splitting.
Thermoelectric materials offer an unambiguous solution to the ever-increasing global demand for energy by harnessing the Seebeck effect to convert waste heat to electrical energy. Mixed-anion materials are ideal candidate...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.