Microwave-Aided Synthesis of BiOI/g-C3N4 Composites and Their Enhanced Catalytic Activities for Cr(VI) Removal

Abstract Few-layer g-C3N4 nanosheets (CN-E) were synthesized by flash freezing the bulk g-C3N4 together with thermo-exfoliation with different time (2-20 min) by microwave assistant, to reduce the thickness of g-C3N4. Then, BiOI nanoflowers were grown in situ on CN-E by microwave-aided synthesis, forming BiOI/CN-E nanocomposites. The BiOI/CN-E showed a best activity of 27% improved Cr(VI) removal efficiency compared with the un-exfoliated BiOI/g-C3N4. The exfoliating CN-E coated on BiOI formed a heterojunction more efficiency than the two overlaid structure of g-C3N4 and BiOI, thus further improved the specific surface area and the catalytic performance during the treatment for pollutant Cr(VI).