Defective ZnFe2O4 nanorods with oxygen vacancy for photoelectrochemical water splitting. Issue 45 (2nd November 2015) - Kim, Ju Hun
Abstract : A 1D ZnFe2 O4 photoanode is treated under a hydrogen or vacuum atmosphere to improve the photoelectrochemical water oxidation activity up to 20 times. This post-treatment creates oxygen vacancies in the ZnFe2 O4 lattice that serve as a source of electron donors and passivates surface trap sites, and as a result improves charge transfer. Abstract : A one-dimensional zinc ferrite (ZnFe2 O4 ) nanorod photoanode was prepared by a simple solution method on the F-doped tin oxide glass substrate. Thermal treatment under a hydrogen or vacuum atmosphere improved the photoelectrochemical water oxidation activity up to 20 times. The various physical characterization techniques used revealed that oxygen vacancies were created by the treatments in the near surface region, which increased the donor density and passivated the surface states. Hydrogen treatment was more effective and it was important to find optimum treatment conditions to take advantage of the positive role of oxygen vacancy as a source of electron donors and avoid its negative effect as electron trap sites.