ESI. Mat. Lett. Bi2Se3 NPs

Nanoparticles of Bi2Se3 were prepared by hot injection method using bismuth nitrate and 1,3-dimethyl-1H-benzo[d]imidazole-2(3H)-selenone (a cyclic selenourea) synthesized in the laboratory as selenide source. This cyclic selenourea was produced with a yield of 67% by reacting elemental selenium powder with 1,3-dimethyl-1H-benzo[d]imidazol-3-ium iodide made from laboratory reagents. Different solvents: triethanolamine, oleylamine, and oleic acid used in the hot-injection processing affected the shape, composition, and crystallinity of the resulting Bi2Se3 nanoparticles. X-ray diffraction patterns confirm the rhombohedral crystalline structure of the material with an average crystallite size of 13 - 19 nm. FESEM reveals that the material was obtained as nanosheet. Optical diffuse reflectance spectrum of the material suggests an indirect bandgap of 0.78 eV for it