Highly crystalline anatase TiO 2 nanotubes array films enhanced with Bi 2 S 3 for photoelectrochemical applications

The synthesis of bismuth (III) sulphide (Bi 2 S 3 )-sensitized titanium dioxide nanotubes arrays (TiO 2 NTAs) was carried out using the SILAR (successive ionic layer adsorption and reaction) method. The effect of different cycles on the performance of a photoanode made of Bi 2 S 3 /TiO 2 NTAs in photoelectrochemical cells was investigated. Field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy and UV–visible spectroscopy were used to investigate Bi 2 S 3 /TiO 2 NTs morphological, elemental composition, structural and optical absorption, respectively. TiO 2 nanotubes had a tetragonal crystal structure, whereas Bi 2 S 3 had an orthorhombic crystal structure, according to XRD measurements. Absorbance spectra showed that the absorbance edges shifted towards longer wavelengths as the number of cycles increased, showing that the optical properties had significantly improved following deposition. Bi 2 S 3 /TiO 2 NTAs photoanode was proposed as a viable alternative photoanode in photoelectrochemical applications. The photocurrent density of the Bi 2 S 3 /TiO 2 NTAs composite film grew first, then declined as the number of Bi 2 S 3 deposition cycles increased. After three cycles of deposition of Bi 2 S 3 , the Bi 2 S 3 /TiO 2 composite films displayed the highest photoelectrochemical characteristics. The photocurrent density of Bi 2 S 3 -3Cy/TiO 2 NTAs was 1.427 mA cm –2 , about four times that of plain TiO 2 NTAs. The Bi 2 S 3 /TiO 2 NTAs photoanode was offered as a feasible alternative photoanode in photoelectrochemical applications based on the findings of this study.