Zinc Titanium Nitride Semiconductor Toward Durable Photoelectrochemical Applications

Ann Greenaway, Sijia Ke, Theodore Culman, Kevin Talley, John Mangum, Karen Heinselman, Ryan Kingsbury, Rebecca Smaha, Melissa Gish, Elisa Miller, Kristin Persson, John Gregoire, Sage Bauers, Jeffrey Neaton, Adele Tamboli, Andriy Zakutayev

Research output: Contribution to journalArticlepeer-review

16 Scopus Citations

Abstract

Photoelectrochemical fuel generation is a promising route to sustainable liquid fuels produced from water and captured carbon dioxide with sunlight as the energy input. Development of these technologies requires photoelectrode materials that are both photocatalytically active and operationally stable in harsh oxidative and/or reductive electrochemical environments. Such photocatalysts can be discovered based on co-design principles, wherein design for stability is based on the propensity for the photocatalyst to self-passivate under operating conditions and design for photoactivity is based on the ability to integrate the photocatalyst with established semiconductor substrates. Here, we report on the synthesis and characterization of zinc titanium nitride (ZnTiN2) that follows these design rules by having a wurtzite-derived crystal structure and showing self-passivating surface oxides created by electrochemical polarization. The sputtered ZnTiN2 thin films have optical absorption onsets below 2 eV and n-type electrical conduction of 3 S/cm. The band gap of this material is reduced from the 3.36 eV theoretical value by cation-site disorder, and the impact of cation antisites on the band structure of ZnTiN2 is explored using density functional theory. Under electrochemical polarization, the ZnTiN2 surfaces have TiO2- or ZnO-like character, consistent with Materials Project Pourbaix calculations predicting the formation of stable solid phases under near-neutral pH. These results show that ZnTiN2 is a promising candidate for photoelectrochemical liquid fuel generation and demonstrate a new materials design approach to other photoelectrodes with self-passivating native operational surface chemistry.

Original languageAmerican English
Pages (from-to)13673-13687
Number of pages15
JournalJournal of the American Chemical Society
Volume144
Issue number30
DOIs
StatePublished - 2022

Bibliographical note

See NREL/JA-5K00-81896 for preprint as published in ChemRxiv

NREL Publication Number

  • NREL/JA-5K00-83700

Keywords

  • carbon dioxide reduction
  • material synthesis
  • semiconductor discovery
  • solar fuels

Fingerprint

Dive into the research topics of 'Zinc Titanium Nitride Semiconductor Toward Durable Photoelectrochemical Applications'. Together they form a unique fingerprint.

Cite this