The low Pr-doped Bi2O3 photocatalyst was prepared via the acrylamide polymerisation method. The photocatalytic activity of prepared samples was evaluated by degrading methyl orange under visible-light irradiation. In comparison to α-Bi2O3 nanoparticles, 4% Pr-α-Bi2O3 photocatalyst exhibit obviously enhanced photocatalytic performance. The theoretical calculation and experimental results show that Pr doping can extend the optical absorption range from 436 to 518 nm and improve the photocatalytic efficiency from 40.9 to 70.4%. This long-wavelength response can be happened because of Pr doping that gives rise to the modification of electron structure and the hybridisation of the energy levels.
