Dramatic improvement of photocatalytic activity for N-doped Bi2O3/g-C3N4 composites

N-doped Bi2O3/g-C3N4 composite photocatalysts were prepared via a cost-effective and eco-friendly ultrasonic dispersion method. It was shown that N-doped Bi2O3 nanoparticles have been perfectly coated by thin g-C3N4 layers. Under visible-light irradiation, the optimum photocatalytic activity of the composite with 66.7wt% of g-C3N4 is almost 4.6 times as high as that of pure g-C3N4 and 8.2 times of Bi2O3, and the RhB degradation efficiency can reach 94.4% in 15min. The dramatically improved performance of the composite can be attributed to an enhancement of visible-light absorption and a synergistic effect of N-doped Bi2O3 nanoparticles and g-C3N4 coatings. •A cost-effective and eco-friendly ultrasonic dispersion method was used to prepare N-doped Bi2O3/g-C3N4 composite photocatalysts.•A dramatic improvement of photocatalytic activity for the composite photocatalysts was observed.•A proper mechanism for the improvement photocatalytic activity was demonstrated.