Synthesis of bismuth micro- and nanospheres by a simple refluxing method

Well-separated bismuth micro- and nanospheres were successfully prepared from bismuth citrate and urea by a simple refluxing reaction at 198 °C in ethylene glycol in the presence of poly(vinyl pyrrolidone) (PVP). The products were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray microanalysis (EDX). The larger Brunauer–Emmett–Teller (BET) surface area of these micro- and nanospheres was found to be 17.34 m2/g by the results of N2 adsorption. It was found that the amount of PVP have an influence on the morphologies of bismuth nanostructure. The possible growth mechanism of bismuth micro- and nanospheres was also discussed.