New synthesis of bismuth oxide nanoparticles Bi2O3 assisted by tannic acid

A new and simple method of biosynthesis assisted by tannic acid (C76H52O46) is used to obtain bismuth trioxide nanoparticles Bi2O3 in which the beta-Bi2O3 phase is identified. Synthesis takes place at room temperature and atmospheric pressure from the reduction of bismuth nitrate pentahydrate (Bi(NO3)(3)center dot 5H(2)O) in solution, using tannic acid as a reducing agent and stabilizer. Nanoparticles with an average size of 10.99 +/- 0.27 nm are obtained, and the structural properties of the nanoparticles are observed using transmission electron microscopy techniques, as well as UV-Visible-NIR spectroscopy, with which a semiconductor behavior with band gap within a range of (2.57-3.02) eV is observed. Using Raman spectroscopy, it is possible to observe and identify different normal modes of vibration, characteristic of the beta-Bi2O3 phase.