Enhanced and fast triboelectric degradation of organics through carbon coating of potassium sodium niobate microspheres
摘要
Tribocatalysis is a process which take use of triboelectrification to catalytic degrade organic pollutants. In this study, KNN@C microspheres as a tribocatalyst were fabricated through a two-step hydrothermal method for degrading the common organic dye pollutants such as rhodamine B (RhB), methylene blue (MeBe), and methyl orange (MO) via magnetic stirring. Carbon coating greatly enhances the tribocatalysis activity and rate of KNN microspheres by enhancing electron mobility, reducing bandgap width, and increasing surface active sites. Notably, the KNN@C-0.1 microspheres demonstrated the highest tribocatalytic degradation rate constant of 4.98 min−1 under a mild tribospeed and surface roughness, which is 3.48 times that of KNN. Surface roughness and tribospeed have been found to influence the tribocatalytic activity. When sandpaper served as the bottom friction material and the tribospeed was 3000 rpm, the KNN@C-0.01 microspheres achieved a high degradation rate constant of 19.65 min−1 for RhB solution. Furthermore, the KNN@C microspheres have been confirmed to possess excellent universality, selectivity, and stability. A tribocatalytic mechanism for KNN@C microspheres is proposed. Overall, KNN@C microspheres hold promise for treating dye wastewater by harnessing friction energy, which is abundant in the environment.