Improved photocatalytic properties of Fe(III) ion doped Bi2MoO6 for the oxidation of organic pollutants

Abstract Improving the separation rate of electron-hole pairs by doping ion is an effective means to enhance photocatalytic activity and has aroused research interest in the development of high-efficient photocatalytic materials. To promote the degradation performance of organic pollutants like Rhodamine B (RhB) under visible light irradiation (λ > 420 nm), an Fe3+ doped bismuth molybdate (Fe–Bi2MoO6) composite photocatalyst was synthesized using a simple hydrothermal technique. When the doping amount of Fe3+ was 1 wt%, the composite represented the highest photocatalytic activity with 92.4% RhB removal after 90 min of visible light irradiation, which was 66.3% higher than pristine Bi2MoO6 nanosheets. Trapping experiments and EPR measurements proved that the holes (h+) and superoxide radical (•O2−) were the primary reactive species. Additionally, the introduction of Fe3+ broadened the light absorption range and acted as an n-type impurity to increase the electron density of Bi2MoO6 nanosheets, resulting in improved photocurrent density, increasing carrier capture and prolonging carrier lifetime. Moreover, the Fe–Bi2MoO6 composite had good stability, with its removal rate remaining at 83.2% after four cycles of reuse. The novel Fe–Bi2MoO6 composite photocatalyst was formulated with the aim of realizing a practical method to remove organic pollutants using solar light.