We report the fabrication and the performance in photoelectrochemical water splitting of thin films of electrostatically sprayed nanotextured bismuth vanadate (BiVO4) pillars coated with thin ZnO/TiO2 passivation layers formed by atomic layer deposition. The thin ZnO and TiO2 layers deposited on the BiVO4 nanopillars formed a heterostructure that promoted electron–hole separation and the migration of electrons toward the ITO substrate. The photocurrent density (PCD) of the ZnO/TiO2 coated BiVO4 was 2.5 times higher (2.25 mA/cm2 at 1.2 V (versus Ag/AgCl)) than that of pristine BiVO4 (0.9 mA/cm2 at 1.2 V (versus Ag/AgCl)). We present incident/absorbed photon-to-current efficiency and electrochemical impedance measurements confirming that this improvement is a result of the heterojunction produced by the conformal ZnO/TiO2 coating and discuss the mechanism of this dramatic enhancement of PCD.
Bibliographical noteFunding Information:
This research was supported by the Technology Development Program to Solve Climate Changes of the National Research Foundation (NRF) funded by the Ministry of Science, ICT & Future Planning ( NRF-2016M1A2A2936760 , NRF-2013M3A6B1078879 , and NRF-2017R1A2B4005639 ) – Republic of Korea.
© 2017 Elsevier B.V.
Copyright 2017 Elsevier B.V., All rights reserved.
- Atomic layer deposition
- Bismuth vanadate nanopillar
- Photocurrent density
- Water splitting
ASJC Scopus subject areas
- Environmental Chemistry
- Chemical Engineering(all)
- Industrial and Manufacturing Engineering