An international team led by scientists at the Max Planck Society in Germany has recently developed a type of microbot that can rapidly remove pollutants and heavy metals from industrial wastewater. After recovery and treatment, these pollutants can be recycled, promising an efficient and economical method for wastewater purification.
According to reports, heavy metal pollution in water is a common problem caused by industrial activities, including battery and electronic product manufacturing, mining, and plating. These activities generate heavy metals such as lead, arsenic, mercury, cadmium, and chromium, which pose safety risks to living organisms and the environment. The microbots developed in this new study focus on removing lead from wastewater. They consist of a three-layer structure: the outer layer is graphene oxide, which can absorb lead from the water; the middle layer is nickel, giving the microtube magnetic properties, allowing their movement direction to be controlled by an external magnetic field; the inner layer is platinum, which, when hydrogen peroxide is added to the water, can decompose hydrogen peroxide into water and oxygen, creating tiny bubbles that propel the microtube forward from behind.
Researchers published a paper in the latest issue of Nano Letters, stating that each microbot is smaller than a human hair and can be deployed in thousands into wastewater, autonomously propelling themselves to capture heavy metals in the water. After completing their task, they can be retrieved using a magnetic field, and lead ions can be removed using an acid solution, allowing them to be restored and reused.
Samuel Sanchez, co-author of the paper and a researcher at the Max Planck Institute for Intelligent Systems, stated that this represents a new application of intelligent nanoscale devices in environmental remediation. This self-propelling nanomachine is used to capture heavy metals in wastewater and transfer them to another location or a certain “closed-loop system.” This research brings us a step closer to developing intelligent remediation systems that allow targeted removal of trace pollutants without generating new pollution.
In the future, automated systems could control large numbers of microbots, guiding them to complete various tasks through magnetic fields. Sanchez mentioned that they also plan to extend the use of these microbots to remove other pollutants. Additionally, the design of this self-propelling mechanism with a functional outer layer can also be applied in other fields such as drug delivery and sensors.
Original text: Graphene-Based Microbots for Toxic Heavy Metal Removal and Recovery from Water