Crucial Effect of Halogen on the Photocatalytic Hydrogen Evolution for Bi19X3S27 (X = CI, Br) Nanomaterials

Halogen has a significant effect on the photo catalytic performance of bismuth chalcohalide (Bi19X3S27, X = CI, Br), which is a class of unique material that holds a bright future and is used in hydrogen energy evolution. To systematically research the influence of halogen, the hydrogen evolution of Bi19X3S27, which has not been identified yet, was studied in this work rigorously. The Bi19Br3S27 sample prepared at 200 degrees C possessed optimal crystallinity and hydrogen evolution rate of 466.7 mu mol g(-1) h(-1), higher than that of samples prepared at other temperatures. It is worth mentioning that with the rising of temperature, both metallic bismuth and sulfur vacancies accepted electrons during the photocatalytic process, thus hindering hydrogen evolution. For Bi19C13S27 nanorods, the sample synthesized at 180 degrees C showed the best activity of 195.1 mu mol g(-1) h(-1); this performance distinction is attributed to the different properties of halogen. Compared with BiOBr on hydrogen evolution ability, Bi19Br3S27 is also far ahead, illustrating the disparity of sulfide and oxide. This study provided a systematic research of restricted and rarely reported Bi19X3S27 materials and opened the door for further thorough and deep exploration of Bi19X3S27.