TY - JOUR

T1 - Electronic structure and water induced phase transformation in layered perovskite-like K2La2Ti3O10 photocatalyst for water splitting studied by DFT

AU - Shvalyuk, Daria

AU - Shelyapina, Marina

AU - Zvereva, Irina

PY - 2023/8/1

Y1 - 2023/8/1

N2 - Layered perovskite-like oxide K2La2Ti3O10 is a perspective photocatalyst for water decomposition at ultraviolet irradiation. In this paper using a density functional theory approach electronic structures of dehydrated and hydrated phases of K2La2Ti3O10 have been studied. It has been found that the water induced phase transformation from I4/mmm to P4/mmm occurs in two steps: at first an increase in the distance between the perovskite layers prevails, and then a shift of the perovskite layers occurs with a moderate changing of the interlayer distance. The band structure calculations have done using the modified Becke-Johnson potential show that K2La2Ti3O10 exhibits indirect band gap of about 3.1 eV. The valence band maximum potential is located at 2.23 eV (vs. normal hydrogen electrode), while the conduction band minimum potential is at −0.91 eV. This confirms the ability of K2La2Ti3O10 both for photocatalytic oxidation of water (producing dioxygen and protons) or pollutants, and to reduce H+ to H2. However, the transfer rate, estimated implicitly from the ratio of the effective masses of the photogenerated holes and electrons in valence and conduction bands, limits photocatalytic performance of K2La2Ti3O10 due to separation ineffectiveness of charge carriers.

AB - Layered perovskite-like oxide K2La2Ti3O10 is a perspective photocatalyst for water decomposition at ultraviolet irradiation. In this paper using a density functional theory approach electronic structures of dehydrated and hydrated phases of K2La2Ti3O10 have been studied. It has been found that the water induced phase transformation from I4/mmm to P4/mmm occurs in two steps: at first an increase in the distance between the perovskite layers prevails, and then a shift of the perovskite layers occurs with a moderate changing of the interlayer distance. The band structure calculations have done using the modified Becke-Johnson potential show that K2La2Ti3O10 exhibits indirect band gap of about 3.1 eV. The valence band maximum potential is located at 2.23 eV (vs. normal hydrogen electrode), while the conduction band minimum potential is at −0.91 eV. This confirms the ability of K2La2Ti3O10 both for photocatalytic oxidation of water (producing dioxygen and protons) or pollutants, and to reduce H+ to H2. However, the transfer rate, estimated implicitly from the ratio of the effective masses of the photogenerated holes and electrons in valence and conduction bands, limits photocatalytic performance of K2La2Ti3O10 due to separation ineffectiveness of charge carriers.

KW - фотокатализ

KW - теория функционала плотности

KW - слоистые материалы

KW - Density functional theory

KW - Layered perovskite-like titanate

KW - Phase transformation

KW - Photocatalytic properties

KW - Water intercalation

UR - https://www.mendeley.com/catalogue/3a6d054b-7e0b-3a26-8e36-8ab96d259012/

U2 - 10.1016/j.jpcs.2023.111384

DO - 10.1016/j.jpcs.2023.111384

M3 - Article

VL - 179

JO - Journal of Physics and Chemistry of Solids

JF - Journal of Physics and Chemistry of Solids

SN - 0022-3697

M1 - 111384

ER -