A facile and clean synthesis of pure bismuth sulfide iodide crystals

Pure BiSI ( bismuth sulfide iodide) crystals were synthesized directly from the reaction of BiCl3, (NH2)(2)CS, and I-2 through a mild hydrothermal process (160 degrees C for 30 h) after simple filtration and washing. The as-prepared crystals were characterized by XRD, IR, XPS, and SEM. The band gap of the product was calculated to be about 1.8 eV from UV-Vis-NIR results. A possible reaction mechanism was proposed.