Facile synthesis, electronic structure and photocatalytic activity of a novel Bi-based hydroxyl oxalate Bi(C2O4)OH

A novel Bi-based hydroxyl oxalate Bi(C2O4)OH has been successfully synthesized via a facile aqueous precipitation route, and its photocatalytic activity was investigated for the first time. The as-prepared Bi(C2O4)OH nanorods were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–vis diffuse reflectance spectra (DRS) and photoluminescence (PL) spectra. It possesses an indirect-transition optical band gap of 3.73 eV. The electronic structure, density of states as well as light absorption of Bi(C2O4)OH were studied by the first principle calculations. The photocatalytic performance of the samples was determined by photodegradation of Rhodamine B (RhB) in aqueous solution. The results revealed that RhB can be effectively decomposed by Bi(C2O4)OH, and the sample with reactant molar ratio of 1:2 exhibits the highest photocatalytic activity. The active species trapping experiments over Bi(C2O4)OH indicated that the hydroxyl radicals (OH) are the most important active species in the process of RhB photodegradation.