Photochemical formation and photoelectrochemical properties of TiO2/Sb2S3 heterostructures

TLDR: The photocatalytic deposition of antimony(III) sulfide on the surface of TiO 2 films on the conductive FTO glass was investigated in this article, where the photoprocessor yields particles of amorphous and almost stoichiometric Sb 2 S 3 with a size of 150-300nm and spherical micrometer particles enriched with Sb with a Sb:S ratio that decreases gradually from 13:1 in the particle center to 5:1 at the surface.

Abstract: The photocatalytic deposition of antimony(III) sulfide on the surface of TiO 2 films on the conductive FTO glass was investigated. The photoprocess yields particles of amorphous and almost stoichiometric Sb 2 S 3 with a size of 150–300 nm and spherical micrometer particles enriched with Sb with a Sb:S ratio that decreases gradually from 13:1 in the particle center to 5:1 at the surface. Thermal treatment of the FTO/TiO 2 /Sb 2 S 3 films at 350 °C results in the transformation of amorphous antimony(III) sulfide into crystalline stibnite without extensive changes in the film morphology. The crystalline FTO/TiO 2 /Sb 2 S 3 films exhibit photoelectrochemical activity when illuminated in the spectral range of λ  > 350 nm in aqueous solutions of ascorbic acid as a sacrificial electron donor. The maximal photocurrent density generated by the TiO 2 /Sb 2 S 3 heterostructure is higher than the photoresponse of the starting FTO/TiO 2 film by a factor of 3.6. Deposition of an intermediary layer of In x (OH) y S z on the interface between TiO 2 and Sb 2 S 3 results in a further 3-fold increase in the photoelectrochemical activity of the FTO/TiO 2 /Sb 2 S 3 heterostructure.