SrTiO3-CaCr0.5Nb0.5O3 solid solutions as p-type photocatalysts for Z-scheme water splitting under visible light illumination. (10th October 2021) - Gu, Zeming
Graphical abstract: New p-type semiconductors have been developed in solid solution series between SrTiO3 and CaCr0.5Nb0.5O3. These solid solutions are superior photocatalysts for H2 production from water. Z-scheme system containing (SrTiO3)0.85(CaCr0.5Nb0.5O3)0.15, WO3 and I-/IO3- redox couple successfully split water into stoichiometric H2/O2 under visible light illumination Highlights: Solid solutions between SrTiO3 and CaCr0.5Nb0.5O3 has p-type semiconductivity. CaCr0.5Nb0.5O3 has solubility of 15 % in SrTiO3. These solid solutions own intense visible light absorption. These solid solutions are promising H2 evolution photocatalysts under visible light. Overall water splitting is realized in Z scheme system containing these solid solutions. Abstract: P-type semiconductivity has been observed in solid solution series (SrTiO3 )1- x (CaCr0.5 Nb0.5 O3 ) x (0.0 ≤ x ≤ 0.15), which all adopt cubic symmetry and own intense absorption in the visible light region. These solid solutions are superior H2 evolution photocatalysts under visible light illumination (λ ≥ 400 nm). An AQE as high as 1.02 % at 420 ± 20 nm has been achieved at optimal composition (SrTiO3 )0.85 (CaCr0.5 Nb0.5 O3 )0.15 which significantly surpasses the parent compounds. Stoichiometric H2 /O2 production under visible light illumination has been successfully realized using Z-scheme system containing (SrTiO3 )0.85 (CaCr0.5 Nb0.5 O3 )0.15, WO3 and I − /IO3 − redox couple.