SILAR preparation of Bi2S3 nanoparticles sensitized TiO2 nanotube arrays for efficient solar cells and photocatalysts

Abstract

Bi2S3 nanoparticles were deposited on TiO2 nanotube arrays (TiO2 NTs/Bi2S3) by the simple successive ionic layer adsorption and reaction (SILAR) method. The morphology, optical absorption and photoelectrochemical properties of TiO2 NTs/Bi2S3 were investigated by the changing of SILAR cycles. The results indicated that the TiO2 NTs/Bi2S3 (5) prepared with 5 SILAR cycles showed the optimal photoelectrochemical properties. The visible light photocurrent density of TiO2 NTs/Bi2S3 (5) was 5.99 mA/cm2, the photovoltage was −0.29 V/cm2, the flat band was −0.67 V, and the carrier concentration was 1.15 × 1020 cm-3. The TiO2 NTs/Bi2S3 (5) showed the optimal photoelectrocatalytic (PEC) removal efficiencies of rhodamine B (RhB), methyl orange (MO) and Cr(VI). Furthermore, the photoelectrochemical mechanism was tentatively proposed, and the excellent solar absorption and electron transportation were the main reason for the high photoelectric conversion and PEC removal of pollutants.