posted on 2025-01-16, 12:37authored byStefania Wolff, Wiktoria Lipińska, Justyna Gumieniak, Agnieszka Kramek, Karol Załęski, Emerson Coy, Natalia A. Wójcik, Katarzyna Siuzdak
Research on titanium nanotubes modified with metal sulfides,
particularly
bismuth sulfide (Bi2S3), 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 Bi2S3. 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. Additionally, methanol- and 2-methoxyethanol-based processing
allowed uniform deposition of the sulfide, which was not reached for
other solvents. XPS studies not only confirm formation of bismuth
sulfides but also indicate that BixTiyOz compound can
arise that can affect both stability and photoactivity of the electrode
material.