Mechanochemical synthesis of nanostructured Sr(Ti1–xFex)O3–δ solid-solution powders and their surface photovoltage responses

Abstract

A series of nanostructure Sr(Ti1−xFex)O3−δ (STFx, x=0.4, 0.6, 0.8) solid-solution powders were synthesized by mechanochemical approach milling from the mixture of SrO, Fe2O3 and TiO2 metal oxides at room temperature. The XRD results revealed that the perovskite STFx nanoparticles were finally formed with few residual α-Fe2O3 detected dependent on the milling conditions. The structure evolution suggested that the mechanochemical synthesis underwent via a solid-state reaction route to initially form Ti-rich perovskite and then incorporate with the residual α-Fe2O3 to achieve the estimated composition. The synthesized STF08 powders exhibited the significant Surface Photovoltage (SPV) spectrum response both in UV and in visible-light region with p-type semiconductor behavior. This finding suggested that the synthesized STF nanopowders could potentially utilize more solar spectrum energy effectively for photo-oxidation and photo-catalysis applications.