Photocatalytic TiO₂/porous BNNSs composites for simultaneous LR2B and Cr (VI) removal in wool dyeing bath

Titanium dioxide/porous boron nitride nanosheets (TiO₂/P-BNNSs) were prepared to remove dyes (Lanaset Red 2B, LR2B) and heavy metals (hexavalent chromium, Cr (VI)) simultaneously in a simulated wool dyeing bath where pollutants (LR2B or Cr (VI)) and auxiliaries were simultaneously presented. Characterisations of TiO₂/P-BNNSs were carried out by X-ray diffraction (XRD), Flourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM) and N₂ adsorption desorption equilibrium. Application of TiO₂/P-BNNSs for the treatment of LR2B alone, Cr (VI) alone and their mixture in the simulated wool dyeing bath was discussed. Both LR2B and Cr (VI) removal were decreased in the ternary system (LR2B/Cr (VI)/(TiO₂/P-BNNSs)) compared with those in their respective binary systems (LR2B/(TiO₂/P-BNNSs) or Cr (VI)/(TiO₂/P-BNNSs)) in the simulated wool dyeing bath. In spite of these decreases, simultaneous LR2B and Cr (VI) removal was achieved after 5 successive cycles of use of TiO₂/P-BNNSs, which particularly maintained the durability for LR2B removal, implicating their potential for real wool dyeing effluent treatment.