A key open question in the study of layered superconducting nickelate films is the role that hydrogen incorporation into the lattice plays in the appearance of the superconducting state. Due to the challenges of stabilizing highly crystalline square planar nickelate films, films are prepared by the deposition of a more stable parent compound which is then transformed into the target phase
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- 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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