Magnetoelectrochemical Rotation of Light Emitting Graphene Monolayers

Light-emitting dynamic systems have attracted significant attention due to their wireless control, high sensitivity, short response-time, and self-mixing capability. Although, among the different propulsion mechanisms, magnetically-driven motion is a common approach, it requires the use of ferromagnetic components and complex electromagnetic set-ups. In this work, a wireless light-emitting monolayer graphene rotor is designed, powered by the synergetic effect between a magnetic field-enhanced electrophoretic propulsion mechanism and electrochemiluminescence (ECL) generated by the model [Ru(bpy)₃]²⁺/tri-n-propylamine system. The asymmetric polarization of a graphene monolayer triggers the reduction of water and the oxidation of the luminophore/co-reactant system, resulting in an observable ECL readout. Simultaneously, a Lorentz force, orthogonal to the plane defined by the external electric and magnetic fields, is induced on the charge compensating ionic flux alongside the device. The combination of both physical chemistry processes is the driving force to trigger light emission and rotational displacement. The efficient coupling of the direction of the global applied electric field and the orientation of the magnetic field allows generating a predictable clockwise (CW) and counterclockwise (CCW) rotation of the 2D nanomaterial, which can be monitored by the ECL emission.