Excellent photoelectrochemical activity of Bi2S3 nanorod/TiO2 nanoplate composites with dominant {001} facets

In this work, {001} facets exposed TiO2 nanoplates were loaded with Bi2S3 nanorods. The resulting Bi2S3/TiO2 photocatalyst exhibits considerable improvement in photoelectrochemical H2 generation than pristine TiO2 nanoplates and Bi2S3 nanorods. The previous research mainly focused on the composite of Bi2S3 nanoparticles with rod-shaped TiO2, and utilized the advantage of large surface area of rod-shaped TiO2 to collect carriers. The advantage of this study is that Bi2S3 is supported on the {001} facets of TiO2 nanoplates, and the high-energy {001} facets and Bi2S3 are used to construct the heterojunction. The experimental results show that the Bi2S3/(001)TiO2 heterojunction has excellent photoelectrochemistry performance, and the photocurrent density of the composite photocatalyst is 20 times larger than that of the original TiO2, which is much higher than the 3–4 times of the literature. Experimental results confirm that {001} facets exposed TiO2 nanoplates are suitable for compositing with Bi2S3 to improve photoelectrochemical performance, which can be ascribed to the photoinduced carriers' synergistic effect between TiO2 and Bi2S3. Thus, photo-generated electrons shift from the conduction band (CB) of Bi2S3 nanorods to the CB of TiO2 nanoplates after photo excitation, while photo-generated holes shift from the valence band (VB) of TiO2 nanoplates to the VB of Bi2S3 nanorods. Here, we demonstrate the significance of semiconductors composites in the improvement of photocatalysts.