Bi2S3-modified TiO2 nanotube arrays: easy fabrication of heterostructure and effective enhancement of photoelectrochemical property

A novel heterostructure of Bi 2 S 3 nanoparticles (NPs) and TiO 2 nanotube arrays (NAs) was fabricated by a conventional hydrothermal method. The morphological features and the X-ray diffractogram of the obtained Bi 2 S 3 /TiO 2 NAs were characterized by field-emission scanning electron microscopy, transmission electron microscopy, and powder X-ray diffraction. The photoelectrochemical property of Bi 2 S 3 /TiO 2 NAs was also evaluated. The results demonstrated that photoelectrochemical solar cells based on Bi 2 S 3 /TiO 2 NAs had a short-circuit current of 4.54 mA/cm 2 and photoelectric conversion efficiency of 1.86 %. Surface photovoltage spectroscopy and field-induced surface photovoltage spectroscopy data indicated the existence of a strong interfacial electronic field between the two components Bi 2 S 3 NPs and TiO 2 NAs, which can enhance the separation of photogenerated charge carriers.