Eco-friendly porous iron(iii) oxide micromotors for efficient wastewater cleaning

Abstract

We present catalytic micromotors based on iron(III) oxides (Fe₂O₃) obtained by thermal decomposition of octahedral Prussian Blue (PB) microcrystals for efficient adsorption of organic pollutants in water. These porous Fe₂O₃ micromotors display effective autonomous motion in hydrogen peroxide (H₂O₂) and long stable movement life up to 2 hours. The speed of the micromotors greatly increases from 14.73 μm s⁻¹ to 64.70 μm s⁻¹ with the fuel concentration increased from 1% to 10%. Moreover, they show excellent performance in efficient adsorption of methyl blue (MB) and exhibit controllable motion under an external magnetic field owing to the presence of γ-Fe₂O₃. Such Fe₂O₃ micromotors hold great potential as an eco-friendly, recyclable and mass-produced candidate for water cleaning in environmental applications.