An investigation of the optical properties and water splitting potential of the coloured metallic perovskites Sr1-xBaxMoO3

Abstract The solid solution Sr 1− x Ba x MoO 3 ( x =0.00, 0.025, 0.050, 0.075, 0.100 and 1.00) has been synthesised. Rietveld refinement of X-ray diffraction data shows that all materials crystallise with cubic ( Pm- 3 m ) symmetry and that a miscibility gap exists from x =0.1–1.0. The optical properties of the metallic perovskites Sr 1− x Ba x MoO 3 have been investigated by a combination of UV–vis spectroscopy and density functional theory (DFT). Upon increasing x from 0 to 1 in Sr 1− x Ba x MoO 3 there is a reduction in the measured band gap from 2.20 eV to 2.07 eV. The measured band gap is attributed to the electronic transition from the Mo 4d t 2g band to the e g band. The potential of SrMoO 3 and BaMoO 3 as water-splitting photocatalysts was explored but there was no evidence of hydrogen or oxygen evolution, even with the presence of a Pt co-catalyst.