Self-propelled Bi2MoO6@MnO2@CuS tubular micromotors for photo-assisted Fenton-like treatment of rare earth ore processing wastewater

The large amount of mineral processing wastewater generated during the extraction of rare earth elements, especially the organic flotation reagents inside, has posed great environmental threats. In this work, a facile method to prepare tubular micromotors based on CuS and MnO 2 was proposed, followed by further integration of Bi 2 MoO 6 on the micromotor surface to enhance the photocatalytic activity. The resulting Bi 2 MoO 6 @MnO 2 @CuS tubular micromotors which could realize autonomous motion by the generation of abundant micro/nanobubbles were employed for the removal of salicylhydroxamic acid (SHA), a commonly used reagent in rare earth ores flotation, via photo-assisted Fenton-like processes. The incorporation of Bi 2 MoO 6 in the tubular structure increased the SHA removal efficiency under visible light by 32.51 %. Moreover, the synergistic effect between photocatalysis and Fenton-like processes contributed to a SHA removal efficiency of 95.51 % within 30 minutes. A possible mechanism was proposed to explain the enhanced catalytic activity of the tubular micromotors. This study provides a way to fabricate tubular micromotor with low-cost and stable materials in batches, which may shed light on the treatment of rare earth ore processing wastewater.