Engineering the direct Z-scheme systems over lattice intergrown of
MOF-on-MOF for selective CO2 photoreduction to CO
Abstract
The direct Z-scheme provide a potential strategy for high efficient CO2
photoreduction, whereas the heterointerface contact resistance is
significantly limited the interfacial electron transfer kinetic. Herein,
we build the directional charge-transfer channels in a direct Z-scheme
system over metal−organic frameworks (MOFs), that is the lattice-guided
MOF-on-MOF hybrids, to facilitate CO2 photoreduction. The
heteroepitaxial lattice growth along the c-axis of MIL-88B(Fe) via the
high-activity (001) facet over the stable (111) facet of UiO-66-NH2.
Theoretical calculations and experimental results provide the direct
evidence that engineering direct Z-scheme of these MOFs hybrids can
induce the electrons migration from UiO-66-NH2 to the holes of
MIL-88B(Fe) by directional charge-transfer channels owing to their
lattice match. This can dramatically boosts photocatalytic CO2-to-CO
selectivity up to nearly 100%, with a rate of 2.26 μmol·g-1·h-1. This
work demonstrates that the efficiently selective CO2 photoreduction
processes can be achieved by engineering Z-scheme via lattice intergrown
of MOF hybrids strategy.