Semiconductor crystals
with well-defined morphology, porous nanostructure,
and spatially separated active sites are attractive for use in photocatalysis.
This paper describes a controlled synthesis of cake-like porous TiO2 photocatalyst with surface-localized doping of copper and
cobalt by using a well-defined MIL-125(Ti)
metal organic framework as template precursor. The series of the modified
TiO2 photocatalysts present the improved activity for photocatalytic
CO2 reduction with water vapor. It is found that 1%Cu-doped
TiO2 shows an enhanced behavior for breaking CO
bonds. In this case, the outcomes are primarily CO and CH4, yielding up to 135.94 and 127.05 μmol, respectively, under
the irradiation of simulated sunlight for 3 h. The performance can
be further improved by incorporating trace cobalt. Besides the improved
property for CO and CH4 production, the selectivity also
shifts to high-value hydrocarbons (C2+). The yields for
C2H6 and C3H8 can be up
to 267.60 and 10.07 μmol, respectively, by using 0.02%Co-1%Cu/TiO2. Our in situ Fourier transform infrared spectra together
with theoretical calculations indicate that efficient charge separation
on copper and cobalt ions is achieved. This altered charge behavior
leads to the generation and enrichment of methyl radicals on the surface
of cobalt ions, giving rise to the production of C2+ hydrocarbons.
This work demonstrates a vibrant catalyst platform for solar fuel
generation by photocatalytic CO2 conversion in water.
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.