Microstructural properties and persulfate activation evaluation of cobalt-doped copper bismuth oxide

Co-doped CuBi2O4 has been successfully prepared by a facile hydrothermal process. The microstructural properties of the ternary oxide were studied using Williamson-Hall and Rietveld analyses, while the persulfate activation activity was evaluated for tetracycline degradation. The effect of Co composition on the lattice strain, crystallite size, and cell volume of the compounds was systematically studied. The crystallite size calculated from Scherrer's equation and Williamson-Hall analysis was in the range of 23.8-28.1 nm and 22.4-25.7 nm respectively. The cell volume calculated from the Rietveld analysis was in the range of 420.9-421.5 x 106 pm. No significant alteration in the lattice parameters of the Co-CuBi2O4 was observed when compared to pristine CuBi2O4. These relatively constant microstructural properties were accounted for by the small amount of Co in the CuBi2O4 crystal. The persulfate activation study showed an increase in activity with doping concentration. The highest efficiency of 91.5 % was achieved over 120 min with 5 mM of persulfate and 10 mg of Cu0.93Co0.07Bi2O4. A maximum degradation activity was achieved at pH of 7, while the radical scavenging studies showed that the mechanism was through a non-radical process involving the generation of 1O2. The influence of Co doping on the microstructural properties of CuBi2O4 and its positive influence on the persulfate activation activity for tetracycline degradation have been established in this study.