BiOX-loaded biohybrid magnetic microrobots for enhanced photocatalysis under visible light

Wastewater remediation towards organic pollutants has attracted increasing interest, and various photocatalysts for decontamination have been explored recently. However, it is still challenging to achieve versatile photocatalytic platforms with superior working efficiency, flexible operation, and good recycling capability. In this work, a novel universal strategy was developed to construct BiOX-loaded biohybrid magnetic microrobots (BiOX BMMs, X=Cl, Br, I) based on Chlorella (Ch.), and their photocatalytic performances on degradation of typical organic pollutants were studied in detail. In this approach, Ch. cells were used as biotemplates, where Fe₃O₄ and BiOX nanoparticles were deposited in sequence to fabricate various types of BiOX BMMs. Thereon, the BiOBr BMMs exhibited the best photocatalytic performance and were focused for further tests. They could be stimulated to degrade methylene blue and tetracycline hydrochloride under visible light irradiation. Besides, they were capable of flexible propulsion under magnetic actuation, which were also endowed with enhanced photocatalytic efficiency and facile recycling capability. Moreover, scavenger tests were conducted to reveal the corresponding photocatalytic mechanisms. The demonstrated strategy offers a significant paradigm to construct remarkable microrobotic platforms with great potentials in pollutant degradation.