Selective preparation of Bi2O3 visible light-driven photocatalyst by dispersant and calcination

• Effect of PEG with different molecular weight on Bi2O3 was first reported.
• N-doped β-Bi2O3 was first selectively synthesized via the method in this work.
• Approximately 96.5% of malachite green was removed by N-doped β-Bi2O3.

Bi2O3 visible light responsive photocatalysts were synthesized by chemical precipitation and consequent calcination process. The as-prepared samples were characterized with XRD, FESEM, UV–Vis and PL methods and their photocatalytic activities were evaluated by degrading malachite green. Last, N-doped β-Bi2O3 with average length of about 252 nm was selectively fabricated under the optimal preparation conditions obtained by investigating influence of dispersant type, dispersant dosage, calcination temperature and time on Bi2O3 crystalline phase, morphology and other performances. The photocatalyst had strong absorption for visible light and efficient separation of charge carrier, which made it a good photocatalyst towards degradation of malachite green. Approximately 96.5% of malachite green was degraded after illumination for 300 min.