The preparation, load and photocatalytic performance of N-doped and CdS-coupled TiO2

Various combinations of N-doped and CdS-coupled TiO2 photocatalysts were studied for MO (methyl orange) degradation under visible light. The photodegradation of MO showed that CdS/N–TiO2 was extremely sensitive to visible light and exhibited much higher activity than N–TiO2 and CdS/TiO2. The results indicated that the semiconductor coupled and N-doped modifications could enhance the photocatalytic performance. The absorption wavelength of CdS/N–TiO2 was extended to 630 nm. The photocatalyst was then loaded on the Activated Carbon Fibers (ACFs) which could be activated by water vapor at 800 °C. In addition, the photodegradation rate of cyclic usage of the photocatalysts was also confirmed. The degradation efficiency of methyl orange with CdS/N–TiO2/ACFs was markedly higher than for the ACF and CdS/TiO2/ACFs composites. The photocatalysts were tightly bound to the ACFs and could be easily handled and recovered from water. At the same time, loading the photocatalysts onto the ACFs could reduce Cd2+ leaching efficiently, from 38% to 7% approximately