SrTiO3-CaCr0.5Nb0.5O3 solid solutions as p-type photocatalysts for Z-scheme water splitting under visible light illumination

P-type semiconductivity has been observed in solid solution series (SrTiO3)(1-x)(CaCr0.5Nb0.5 O-3)(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 H-2 evolution photocatalysts under visible light illumination (lambda >= 400 nm). An AQE as high as 1.02 % at 420 +/- 20 nm has been achieved at optimal composition (SrTiO3)(0.85)(CaCr0.5Nb0.5O3)(0.15) which significantly surpasses the parent compounds. Stoichiometric H-2/O-2 production under visible light illumination has been successfully realized using Z-scheme system containing (SrTiO3)(0.85)(CaCr0.5Nb0.5O3)(0.15), WO3 and I-/IO3- redox couple. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

P-type semiconductivity was observed in the solid solution series (SrTiO3)(1-x)(CaCr0.5Nb0.5 O-3)(x) (0.0 <= x <= 0.15), which showed superior H-2 evolution photocatalytic performance under visible light, with an optimal composition achieving an AQE of as high as 1.02%. The Z-scheme system containing (SrTiO3)(0.85)(CaCr0.5Nb0.5O3)(0.15), WO3 and I-/IO3- redox couple successfully realized stoichiometric H-2/O-2 production under visible light illumination.