title: Investigating the behavior of various cocatalysts on LaTaON2photoanode for visible light water splitting.
abstract: We performed a comparative study on the photoelectrochemical performance of LaTaON2loaded with NiOx, Ni0.7Fe0.3Ox, CoOxand IrOxas cocatalysts. Ni-based oxides lead to the highest improvement on the photoelectrochemical performance, while CoOxand IrOxalso enhance the performance though to a lower extent, but they simultaneously introduce more pseudocapacitive current thus resulting in an inefficient utilization of the photo-generated holes. Repetitive voltage cycling between 1.0 VRHEand 1.6 VRHEtransforms the NiOxand Ni0.7Fe0.3Oxinto oxyhydroxides known to possess higher catalytic activities. However, these oxyhydroxides lead to lower photoelectrochemical performance compared to the as-loaded oxides, most probably due to the decay of the passivation centers at the photoelectrode-cocatalyst interface. High catalytic activities cannot be achieved without sufficient passivation of surface recombination states. Despite that the photoelectrochemical performance of LaTaON2can be improved by cocatalysts, the maximum achievable photocurrent density is still not comparable to that reported for other oxynitride compounds. Our study suggests that poor electronic conductivity or severe bulk recombination of the photo-generated electron-hole pairs are the main limiting factors for the photon-to-current conversion efficiency in LaTaON2photoanodes.
authors.affiliation: Thin Films and Interfaces, Research with Neutrons and Muons Department, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland. thomas.lippert@psi.ch.
authors.forename: Wenping
authors.identifier: http://orcid.org/0000-0002-3064-1533
authors.initials: W
authors.lastname: Si
authors.affiliation: Thin Films and Interfaces, Research with Neutrons and Muons Department, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland. thomas.lippert@psi.ch.
authors.forename: Daniele
authors.initials: D
authors.lastname: Pergolesi
authors.affiliation: Thin Films and Interfaces, Research with Neutrons and Muons Department, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland. thomas.lippert@psi.ch.
authors.forename: Fatima
authors.initials: F
authors.lastname: Haydous
authors.affiliation: Thin Films and Interfaces, Research with Neutrons and Muons Department, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland. thomas.lippert@psi.ch.
authors.forename: Aline
authors.identifier: http://orcid.org/0000-0003-1532-7068
authors.initials: A
authors.lastname: Fluri
authors.affiliation: Thin Films and Interfaces, Research with Neutrons and Muons Department, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland. thomas.lippert@psi.ch.
authors.forename: Alexander
authors.initials: A
authors.lastname: Wokaun
authors.affiliation: Thin Films and Interfaces, Research with Neutrons and Muons Department, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland. thomas.lippert@psi.ch and Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, 8093 Zurich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Lippert