1570
Evaluation of Material Properties and Performance of Zinc Ferrite (ZnFe2O4) for Photoelectrochemical Water-Splitting

Wednesday, 31 May 2017
Grand Ballroom (Hilton New Orleans Riverside)
J. Bright and N. Wu (West Virginia University)
With greenhouse gases such as methane and carbon dioxide contributing significantly to global climate change, sustainable, carbon-neutral fuels are needed to replace fossil fuels for meeting society’s energy needs. A possible replacement for fossil fuels for energy is hydrogen gas derived from photoelectrochemical (PEC) water-splitting. However, existing materials capable of driving photoelectrochemical water-splitting have several problems not limited to poor light absorption at visible wavelengths that compromise the sunlight, poor charge transport within the material, and/or poor photo-stability in aqueous electrolyte solutions. Therefore, new materials must be developed or efforts must be made to solve the issues of existing materials for PEC water-splitting.

Zinc ferrite (ZnFe2O4) is a n-type, narrow bandgap (Eg = 1.9 eV) semiconductor with a sufficiently positive valence band to drive PEC water-splitting as a photoanode. However, ZnFe2O4 suffers from multiple issues that lower its performance for PEC water-splitting such as extremely poor conductivity, poor light absorption despite its narrow bandgap due to the bandgap’s indirect nature, and poor surface catalytic activity. This work fundamentally studies ZnFe2O4 by quantifying its optical, electrical, and catalytic properties and comparing these properties to other established materials for PEC water-splitting. Based on this study, the critical limiting factors for ZnFe2O4’s implementation as a photoanode for PEC water-splitting will be discussed.