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

Abstract

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.