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.

Dye wastewaters are produced in huge amounts every year world-widely and they pose serious threats to ecosystems and human health if not treated properly. High-concentration organic dye wastewaters are usually treated through multiple steps including pretreatment and advanced treatment. In this work, TiO₂ nanoparticles suspended in high-concentration rhodamine B (Rh B) solutions up to 500 mg/L have been subjected to magnetic stirring to initiate tribocatalytic degradation of Rh B. While 100 and 200 mg/L Rh B solutions can be rather thoroughly degraded in beakers with four kinds of bottom/coatings (glass, Al₂O₃, Ti, and PTFE), 300 mg/L Rh B solutions can only be degraded effectively in a beaker with PTFE coating. Even 400 and 500 mg/L Rh B solutions can also be degraded rather thoroughly by TiO₂ nanoparticles in a PTFE-coated beaker. EPR analyses revealed that PTFE coating enhanced the formation of both hydroxyl radicals and superoxide radicals by magnetic stirring-stimulated TiO₂ nanoparticles. These findings highlight the importance of the synergism between materials in friction pairs for tribocatalysis and demonstrate a one-step tribocatalytic degradation of Rh B solutions with concentrations of real Rh B wastewaters.

Coating disk-shaped materials on the bottoms of containers has become a highly effective method for tribocatalysis enhancement. Presently, the effects of Ti coatings on the tribocatalytic degradation of organic dyes by CdS nanoparticles have been 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 than in 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 have been identified between Ti and Al2O3 coatings. Electron paramagnetic resonance (EPR) spectroscopy analyses showed that more radicals were generated when CdS nanoparticles rubbed against Ti coating than glass bottom, and boron nitride nanoparticles had been employed to verify that the enhancement associated with Ti coatings resulted from the interactions between Ti and CdS. These findings underscore the importance of catalysts and coating materials selection in tribocatalytic systems, offering valuable insights for the development of efficient environmental purification technologies.