Magnetically recyclable and remarkably efficient visible-light-driven photocatalytic hexavalent chromium removal based on plasmonic biochar/bismuth/ferroferric oxide heterojunction

The development of easily recyclable non-noble metal plasmonic photocatalysts with high performance is highly desired for the removal of Cr(VI) Herein, the in-situ growth of plasmonic-bismuth (Bi) combined with magnetic ferroferric (Fe3O4) nanoparticles on biochar (BC) was realized by a facile high temperature calcination. BC/Bi/Fe3O4 exhibits broad photoabsorption from 200 to 2000 nm. The weaker photoluminescence (PL) spectrum or stronger photocurrent density confirmed its higher separation efficiency of photogenerated carriers than that of BC or Bi/Fe3O4. Under visible light irradiation, BC/Bi/Fe3O4 exhibits excellent adsorption-photocatalytic performance for Cr(VI) (95%) in 180 min.