Hybrid nanocomposite with visible–light photocatalytic activity: CdS–pillared titanate

CdS–pillared titanate as an efficient visible–light active photocatalyst has been synthesized through a simple reassembling reaction between negatively charged titanate sheets and positively charged CdS colloid nanoparticles. The formation of the heterostructure with the interlayer spacing of 2.7 nm was clearly evidenced by powder X–ray diffraction and high–resolution transmission electron microscopic analysis. The diffuse reflectance UV–visible measurement demonstrated that the nanocomposite displays dual band–gap character with Eg = 3.47 and 2.24 eV, corresponding to the values for titanate host layers and CdS nanoparticles, respectively, and the optical feature of CdS nanoparticles make them as the sensitizers to photosensitize titanate host layers under visible–light irradiation. The test of photocatalytic activity revealed that the methylene blue molecules could be photodegraded effectively under the visible–light irradiation (λ > 420 nm).

► CdS–pillared titanate nanocomposite has been synthesized via exfoliation–restacking technique. ► CdS–pillared titanate nanocomposite shows spectral response in the visible–ight region. ► Dye can be degraded effectively by the catalyst under visible light irradiation.