Jump to main content
Jump to site search


A multitude of modifications strategy of ZnFe2O4 nanorod photoanodes for enhanced photoelectrochemical water splitting activity

Author affiliations

Abstract

Numerous modifications strategies are applied to spinel ZnFe2O4 nanorods with a band gap energy of ∼2.0 eV to enhance their activity as a photoanode for photoelectrochemical (PEC) water splitting. First, hybrid microwave annealing (HMA) imparts high crystallinity to ZnFe2O4 nanorods, while preserving the formed nanostructure and maintaining high electric conductivity of F:SnO2 (FTO) substrate. This is in contrast to conventional thermal annealing (CTA) at 800 °C that causes aggregation of ZnFe2O4 and degradation of FTO. Second, insertion of a TiO2 underlayer blocks charge recombination at the FTO/electrolyte interface and serves as a source of Ti doping. Third, hydrogen treatment yields oxygen vacancies that increase charge carrier density and cause surface passivation. Last, a NiFeOx co-catalyst promotes hole injection into the electrolyte to improve catalytic water oxidation activity. These synergistic modifications lead to enhanced photocurrent density from 0.025 mA cm−2 at 1.23 VRHE for pristine ZnFe2O4 nanorods prepared by CTA to 0.92 mA cm−2 for a fully modified HMA photoanode: a 37-fold increase in photocurrent density. There is also a cathodic shift of the onset potential down to 0.62 VRHE. The multiple modifications enhance bulk charge separation efficiencies from mere 2% to 30% and surface charge separation efficiency from 40% to 80%.

Graphical abstract: A multitude of modifications strategy of ZnFe2O4 nanorod photoanodes for enhanced photoelectrochemical water splitting activity

Back to tab navigation

Supplementary files

Publication details

The article was received on 07 Mar 2018, accepted on 31 May 2018 and first published on 04 Jun 2018


Article type: Paper
DOI: 10.1039/C8TA02161A
Citation: J. Mater. Chem. A, 2018, Advance Article
  •   Request permissions

    A multitude of modifications strategy of ZnFe2O4 nanorod photoanodes for enhanced photoelectrochemical water splitting activity

    J. H. Kim, Y. J. Jang, S. H. Choi, B. J. Lee, J. H. Kim, Y. B. Park, C. Nam, H. G. Kim and J. S. Lee, J. Mater. Chem. A, 2018, Advance Article , DOI: 10.1039/C8TA02161A

Search articles by author

Spotlight

Advertisements