Solvent Selection as a Key Factor in the Performance of Semitransparent Heterojunctions Composed of Hydrogenated Nanotubes and Bismuth Sulfides.

Research on titanium nanotubes modified with metal sulfides, particularly bismuth sulfide (BiS), aims to create heterostructures that efficiently absorb sunlight and then separate photogenerated charge carriers, thereby enhancing the energy conversion efficiency. This study shows a key role of solvent used for sulfide and bismuth salt solutions used during successive ionic layer adsorption and reaction (SILAR) onto the morphology, structure, and photoresponse of the heterojunction where one element is represented by semitransparent titania nanotubes (gTiNT) and the second is BiS. Using 2-methoxyethanol and methanol during SILAR, results in remarkably photoactive 3D heterostructure and recorded photocurrents were 44 times higher compared to bare titania nanotubes.

Transparent TiO nanotubes supporting silver sulfide for photoelectrochemical water splitting.

Differences between photoelectrochemical and electrochemical activity were thoroughly investigated for the oxygen evolution reaction mediated by AgS deposited on two types of ordered titania substrates. Titanium dioxide nanotubes were fabricated by anodization of magnetron sputtered Ti films on ITO-coated glass substrates or directly from Ti foil. Further, AgS deposition on the nanotubes was carried out using successive ionic layer adsorption and reaction, known as SILAR, with 5, 25, and 45 cycles performed.