Pickering‐Engineered Microparticles for Magnetically Guided Motion and Light‐Triggered Catalysis

ABSTRACT We report a holistic design strategy for magnetically and photoactively functional hybrid microparticles formed by the self‐assembly of hematite (α‐Fe 2 O 3 ) cubes anchored at the surface of solid wax spheres through a Pickering emulsification process. In this multicomponent synthesis, the hematite cubes and wax each play multiple, cooperative roles that collectively determine the morphology and functionality of the resulting particles: the liquid wax promotes efficient packing and magnetic coupling of the cubes at the interface; the solidified wax core provides structural stability and mobility; and the hematite cubes confer both magnetic responsiveness and visible‐light‐driven catalytic activity. Under an external magnetic field, the particles exhibit controlled motion, and upon visible‐light irradiation, they catalyze the decomposition of hydrogen peroxide, generating oxygen bubbles at their surfaces. This dual magnetic–photocatalytic functionality enables both spatial steering and light‐triggered activation of chemical reactions. The straightforward Pickering‐assisted route thus provides a versatile strategy for producing environmentally benign, self‐assembled microdevices for applications in pollutant degradation, catalytic processes, and soft microrobotics.