Synthesis, structural characterization, and photocatalytic activity of Bi‐based nanoparticles

Abstract Bi‐based nanoparticles were successfully synthesized (500°C/2 h) following two intermediate‐temperature routes, Pechini and a combined method of mechanical milling/molten salts. Herein, α‐Bi ₂ O ₃ /Bi ₂ O ₂ CO ₃ heterostructures were identified. These types of heterostructures have shown advantages to improve the visible light responsive activity of Bi‐based nanoparticles to facilitate the separation of photogenerated electron‐hole pairs. By fixing the experimental parameters, the synthesis route and Ag contents showed to play a very important role in the phase composition of the Ag‐containing samples; the formation of Bi/Ag‐Bi ₂ O ₃ /Bi ₂ O ₂ CO ₃ and Ag/Ag‐Bi ₂ O ₃ /Bi ₂ O ₂ CO ₃ complex hybrid structures were revealed. The α‐Bi ₂ O ₃ /Bi ₂ O ₂ CO ₃ heterostructure prepared by combined method exhibited higher photocatalytic efficiency (66.84%) for degrading methylene blue ( MB ) depending on Bi ₂ O ₂ CO ₃ component proportion. For the Ag‐containing hybrid structures, the performance of their catalytic activity did not show an increase with respect to α‐Bi ₂ O ₃ /Bi ₂ O ₂ CO ₃ . However, in these samples, the degradation efficiency was slightly enhanced with the efficient doping of Ag into the α‐Bi ₂ O ₃ structure and the existence of Bi when the Pechini method was used. Also, a possible photocatalytic process for degrading MB is presented.