Spontaneous locomotion of nano-catalysed BZ droplets

The motion in living systems by chemo-mechanical transduction has inspired the scientists to design and develop self-moving biomimetic systems. Here, we harness self-oscillating Belousov-Zhabotinsky (BZ) reaction, synergized by graphene-based catalytic mats to demonstrate the spontaneous motion of the BZ reaction droplet in oil-surfactant medium. Specifically, we synthesize graphene-based catalytic mats by decorating Ru nanoparticles (NP) on graphene nanosheets, thereby creating 0D-2D heterostructures; subsequently, use these mats to catalyze BZ reaction within a droplet. Our results demonstrate spontaneous locomotion of BZ droplets due to Marangoni flow facilitated by the interaction between BZ reaction intermediates and the surfactant in the surrounding oil. We further show that the velocity of droplet motion depends upon the conductivity of the catalytic mats. In particular, we observe highest droplet velocities when RuNP decorated graphene sheets are used to catalyze the BZ reaction. In addition, we witnessed some interesting behaviours when multiple BZ droplets interact within the oil-surfactant medium. Our findings can be used to design self-moving synthetic systems to control their behavior through the use of 0D-2D hybrid nanomaterials.