Perovskites are promising oxygen carriers for solar‐driven thermochemical fuel production due to higher oxygen exchange capacity. Despite their higher fuel yield capacity, La0.6Sr0.4MnO3perovskite materials present slow CO2‐splitting kinetics compared with state‐of‐the‐art CeO2. In order to improve the CO production rates, the incorporation of Cr in La0.6Sr0.4MnO3is explored based on thermodynamic calculations that suggest an enhanced driving force toward CO2splitting at high temperatures for La0.6Sr0.4Cr
BaTiO3heated in an excess of SrCl2at 1150 °C converts to SrTiO3through an ion exchange reaction. The SrTiO3synthesized by ion exchange produces hydrogen from pH 7 water at a rate more than twice that of conventional SrTiO3treated identically. The apparent quantum yield for hydrogen production in pure water of the ion exchanged SrTiO3is 11.4% under 380 nm illumination. The catalyst resulting from ion‐exchange differs from conventional SrTiO3by having ≈2% residual Ba, inhomogeneous Cl‐doping at a concentration less than 1%, Kirkendall voids in the centers of particles that result from the unequal rates of Sr and Ba diffusion together with the transport of Ti and O, and nanoscale regions near the surface that have lattice spacings consistent with the Sr‐excess phase Sr2TiO4. The increased photochemical efficiency of this nonequilibrium structure is most likely related to the Sr‐excess, which is known to compensate donor defects that can act as charge traps and recombination centers.
more » « less- NSF-PAR ID:
- 10400185
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials Interfaces
- Volume:
- 10
- Issue:
- 10
- ISSN:
- 2196-7350
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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