Ti Coating-Enhanced Tribocatalytic Degradation of Organic Dyes by CdS Nanoparticles

Coating disk-shaped materials on the bottoms of containers has become a highly effective method for tribocatalysis enhancement. Here, the effects of Ti coatings on the tribocatalytic degradation of organic dyes by CdS nanoparticles were systematically studied. For both 50 mg/L rhodamine B (RhB) and 20 mg/L methyl orange (MO) solutions, the tribocatalytic degradation by CdS nanoparticles was dramatically enhanced in Ti-coated beakers compared to as-received glass-bottomed beakers, with the degradation rate constant increased by 4.77 and 5.21 times, respectively. Moreover, for tribocatalytic degradation of MO using CdS, two quite different MO degradation modes were identified between Ti and Al2O3 coatings. Electron paramagnetic resonance (EPR) spectroscopy analyses showed that more radicals were generated when CdS nanoparticles rubbed against the Ti coating than against the glass bottom, and boron nitride nanoparticles were employed to verify that the enhancement associated with the Ti coating resulted from the interactions between Ti and CdS. These findings underscore the importance of catalyst and coating material selection in tribocatalytic systems, offering valuable insights for the development of efficient environmental purification technologies.