Enhancing the active motion of hematite microswimmers

The demand for autonomous, self-propelled active particles is rapidly growing in soft matter research, driven by their potential applications in cargo delivery, environmental remediation, and as valuable models for understanding biological systems. Despite this interest, the challenge of designing highly active and cost-effective microparticles persists. Here, we present a simple and general method to enhance the photocatalytic performance of hematite microparticles through thermal treatment. By calcining the particles in air at 600 °C for varying durations, we achieve significant improvements in their light-driven motility. Optical microscopy tracking reveals up to an 87-fold increase in mean-squared displacement (MSD) at short lag times. Our findings highlight a simple and scalable method to substantially improve the efficiency of hematite microparticles, and this advancement opens new avenues for their application in key areas of soft matter and photocatalysis research.