Synthesis, structure and photocatalytic reactivity of layered CdS/H₂La₂Ti₃O₁₀ nanocomposites

Abstract

A fabrication process has been optimized to produce photocatalytic H₂La₂Ti₃O₁₀/CdS nanocomposites by a stepwise exchanging reaction of H₂La₂Ti₃O₁₀ with n-C₃H₇NH₂ (or n-C₈H₁₇NH₂), Cd(CH₃COO)₂ and H₂S gas, which was obtained by H⁺-exchanging reaction of K₂La₂Ti₃O₁₀ with HCl other than the normally used HNO₃. XRD, TEM, FT-IR, TG, ICP and BET methods were used to investigate the pillaring-process. Results showed that the particle size of pillared cadnium sulphide was less than 1nm and the amount of intercalated CdS increased from 12.2 wt% to 16.5 wt% when n-C₈H₁₇NH₂ took the place of n-C₃H₇NH₂ to “pre-expand” the interlayer of H₂La₂Ti₃O₁₀. The possible reason of this success was mentioned. The photocatalytic properties of the resulting powders were evaluated by using photodecomposition of methyl orange as the model system. Compared with the unpillared K₂La₂Ti₃O₁₀, the pillaring of CdS gave rise to a remarkable enhancement of its photoactivity and the decomposition rate of methyl orange was improved from 50% to 95%.