Solvothermal synthesis of trigonal selenium with butterfly-like microstructure

We present a facile synthesis of trigonal selenium with butterfly-like microstructure from elemental selenium via a solvothermal and aging route. By using X-ray diffraction and scanning electron microscopy to characterize the products, a possible growth mechanism is proposed. The solvothermal process promotes the dissolution of selenium in ethylenediamine to form a brown homogeneous [Se(en)x] solution. By introducing acetone into this [Se(en)x] solution, amorphous selenium nanoparticles were produced which then transformed into trigonal selenium, which further assembled along the c-axis to form hexagonal rods. Owing to stereo hindrance as well as to development of opposite lateral sides of the hexagonal rod in opposing directions, a butterfly-like microstructure consisting of two long outside rods and a short inner rod was obtained.