Band Edge Engineering of Oxide Photoanodes for Photoelectrochemical Water Splitting: Integration of Subsurface Dipoles with Atomic-Scale Control

Yasuyuki Hikita*, Kazunori Nishio, Linsey C. Seitz, Pongkarn Chakthranont, Takashi Tachikawa, Thomas F. Jaramillo, Harold Y. Hwang

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

39 Scopus citations

Abstract

One of the crucial parameters dictating the efficiency of photoelectrochemical water-splitting is the semiconductor band edge alignment with respect to hydrogen and oxygen redox potentials. Despite the importance of metal oxides in their use as photoelectrodes, studies to control the band edge alignment in aqueous solution have been limited predominantly to compound semiconductors with modulation ranges limited to a few hundred mV. The ability to modulate the flat band potential of oxide photoanodes by as much as 1.3 V, using the insertion of subsurface electrostatic dipoles near a Nb-doped SrTiO3/aqueous electrolyte interface is reported. The tunable range achieved far exceeds previous reports in any semiconductor/aqueous electrolyte system and suggests a general design strategy for highly efficient oxide photoelectrodes.

Original languageEnglish (US)
Article number1502154
JournalAdvanced Energy Materials
Volume6
Issue number7
DOIs
StatePublished - Apr 6 2016

Funding

This work was supported by the Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering (heterostructure synthesis), and the Catalysis Science Program within the Chemical Sciences, Geosciences, and Biosciences Division (PEC characterization), under contract DE-AC02-76SF00515, and the Global Climate and Energy Project at Stanford University. L.C.S. acknowledges support from the DARE Doctoral Fellowship supported by the Vice Provost for Graduate Education at Stanford University. P.C. and T.F.J. were supported from an NSF project (award number CBET-1433442) competitively-selected under the solicitation NSF 14-15: NSF/DOE Partnership on Advanced Frontiers in Renewable Hydrogen Fuel Production via Solar Water Splitting Technologies, which was co-sponsored by the National Science Foundation, Division of Chemical, Bioengineering, Environmental, and Transport Systems (CBET), and the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Fuel Cell Technologies Office.

Keywords

  • interface dipoles
  • oxide/electrolyte interfaces
  • photoanodes
  • photoelectrochemical cells
  • solar water splitting

ASJC Scopus subject areas

  • Renewable Energy, Sustainability and the Environment
  • General Materials Science

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