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

Bi-based nanoparticles were successfully synthesized (500 degrees C/2h) following two intermediate-temperature routes, Pechini and a combined method of mechanical milling/molten salts. Herein, -Bi2O3/Bi2O2CO3 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-Bi2O3/Bi2O2CO3 and Ag/Ag-Bi2O3/Bi2O2CO3 complex hybrid structures were revealed. The -Bi2O3/Bi2O2CO3 heterostructure prepared by combined method exhibited higher photocatalytic efficiency (66.84%) for degrading methylene blue (MB) depending on Bi2O2CO3 component proportion. For the Ag-containing hybrid structures, the performance of their catalytic activity did not show an increase with respect to -Bi2O3/Bi2O2CO3. However, in these samples, the degradation efficiency was slightly enhanced with the efficient doping of Ag into the -Bi2O3 structure and the existence of Bi when the Pechini method was used. Also, a possible photocatalytic process for degrading MB is presented.