Synergistic effect of oxygen vacancy and nitrogen doping on enhancing the photocatalytic activity of Bi2O2CO3 nanosheets with exposed {001} facets for the degradation of organic pollutants

Single-crystalline bare Bi2O2CO3 (BOC) nanosheets with exposed {0 0 1} facets and nitrogen-doped Bi2O2CO3 (NBOC) flower-like microstructures were synthesized by a simple hydrothermal method. The nitrogen-doped Bi2O2CO3 flower-like microstructures with oxygen vacancy (UV-NBOC) were obtained by irradiating the NBOC microstructures with UV light for 2 h in ethanol. The UV-vis diffuse reflectance spectra showed that the NBOC and UV-NBOC nanosheets exhibit an obvious red shift in light absorption band compared with the pure BOC nanosheets. Rhodamine B (RhB) was chosen as a model organic pollutant to verify the influence of oxygen vacancy and nitrogen doping on the photocatalytic activity of Bi2O2CO3 under simulated solar light irradiation. Judging from the kinetics of RhB photodegradation over the synthesized samples, a synergistic effect between oxygen vacancy and nitrogen doping was found with a remarkable increase (more than 10 and 2 times) in the photocatalytic activity of UV-NBOC compared with BOC and NBOC, respectively. Moreover, the UV-NBOC also exhibited an excellent cyclability and superior photocatalytic activity toward degradation of other organic pollutants (methylene blue, Congo red, Bisphenol A) under simulated solar light irradiation. (C) 2016 Elsevier B.V. All rights reserved.