Preparation and Photocatalytic Activity of ABi2O6/BiOCl (A = Mg, Sr, Ca) Heterojunction: Photocatalytic activity of ABi2O6/BiOCl

MgBi2O6, CaBi2O6, and SrBi2O6 were successfully synthesized by a substitution reaction of NaBiO3 with MgCl2, CaCl2, and Sr(NO3)(2), respectively. Then, ABi(2)O(6)/BiOCl (A = Mg, Ca, Sr) heterojunction compounds with different ABi(2)O(6):BiOCl ratios were prepared by treating ABi(2)O(6) with an appropriate amount of HCl. The color of the ABi(2)O(6)/BiOCl heterojunction was changed from dark to bright as the amount of BiOCl was increased. The absorbances of the ABi(2)O(6)/BiOCl heterojunctions in the visible range were decreased as the ratio of BiOCl became higher. The photocatalytic activities of the heterojunction samples were higher than that of sole ABi(2)O(6) or BiOCl. The highest photocatalytic efficiency was achieved when the ABi(2)O(6):BiOCl ratio was 15:85. The organic pollutant was decomposed completely within 1 h under visible light when the 15:85 catalyst was used. The reactive species in the photocatalytic reaction with the ABi(2)O(6)/BiOCl photocatalysts were center dot O-2(-) and h(+) H+.