A green method to prepare magnetically recyclable Bi/Bi_(25)FeO_(40)-C nanocomposites for photocatalytic hydrogen generation

摘要

In the present work, magnetically recyclable Bi/Bi_(25)FeO_(40)-C nanocomposites were synthesized through a one-step hydrothermal approach and then analyzed. The analysis results manifested that non-toxic and biodegradable sodium alginate takes a key role in successful preparation of Bi/Bi_(25)FeO_(40)-C. Sodium alginate can totally suppresses the formation of BiFeO_3 because it changes the alkalinity of the medium, and at the same time Fe precursor greatly restrains the reduction of Bi~(3+) to Bi by sodium alginate, so the final product is Bi/Bi_(25)FeO_(40) with a small amount of Bi instead of Bi, BiFeO_3 or Bi/BiFeO_3. Bi/Bi_(25)FeO_(40)-C showed enhanced photocatalytic activity in hydrogen generation as compared with pure Bi_(25)FeO_(40) due to the surface plasmonic resonance effect of Bi and electron conductivity of carbon, which promote electron-hole separation and light absorption of the Bi/ Bi_(25)FeO_(40)-C, resulting in high photocatalytic efficiency. The Bi/Bi_(25)FeO_(40)-C even exhibited higher catalytic efficiency than noble metallic nanoparticles and good reusability in p-nitrophenol reduction. This work provides a green way to prepare Bi/Bi_(25)FeO_(40)-C for catalytic reactions.