A green method to prepare magnetically recyclable Bi/Bi25FeO40-C nanocomposites for photocatalytic hydrogen generation

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.