Hydrothermal Synthesis of Bi2S3Nanorods from a Single-Source Precursor and Their Promotional Effect on the Photocatalysis of TiO2

As a direct bandgap semiconductor, Bi2S3has the potential ability to improve the photocatalytic activity of nano-TiO2due to its low energy gap (Eg=1.3 eV). In this study, large-scale uniform Bi2S3nanorods were synthesized by a hydrothermal treatment, using Bi[S2P(OC4H9)2]3as the single-source precursor. Characterization results show that as-prepared samples belong to an orthorhombic phase of Bi2S3, and the products mainly crystallize in the form of nanorods which measure ca. 200 nm in length and ca. 50 nm in diameter. The photo-catalytic experiments for the degradation of methyl orange under visible irradiation revealed that a small amount of as-prepared Bi2S3in our study would significantly improve the photo-catalytic activity of nano-TiO2, whether Bi2S3is introduced by a physical way or a chemical way. However, excess Bi2S3will lead to a decrease in the catalytic efficiency of TiO2when Bi2S3was introduced by a chemical way; it never happened when Bi2S3was introduced by a physical way. Even so, among all as-prepared samples, the TiO2-based photo-catalyst with 3 wt.% Bi2S3introduced by a chemical way exhibits the best catalytic performance under visible irradiation.