Utilizing Friction Energy on Nanoflowers (Zinc Oxide and Zinc Oxide/Neodymium Oxide) for Tribocatalysis of Doxycycline

Mechanical energy is a plentiful, environmentally friendly, and sustainable energy source in the natural world. In this work, we successfully use friction to transform mechanical energy into ZnO and ZnO/Nd₂O₃ (1, 2, 3, 4 and 5 mol%) tribocatalysts. Under magnetic stirring, the catalyst particles and the polytetrafluoroethylene (PTFE)-sealed magnetic bar rubbed against one another, transferring electrons across the contact interface. While the PTFE absorbed the electrons, holes were simultaneously left on the catalyst. Because of their potent oxidative power, the holes in the valence band of sol-gel catalysts can efficiently oxidize organic pollutants, much like photocatalysis. In the absence of light, the tribocatalytic tests showed that ZnO and ZnO/Nd₂O₃ flowers could remove antibiotics (Doxycycline) when magnetized. We could further improve the tribocatalytic performance by adjusting the quantity of rare earth elements (1, 2, 3, 4 and 5 mol%), stirring speed, and magnetic rod type. Besides creating a green tribocatalysis method for organic pollutants' oxidative purification, this work provides a possible pathway for transforming environmental mechanical energy into chemical energy, which may be applied to environmental remediation and sustainable energy.