CdAl mixed metal oxides prepared by calcination of CdAl layered double hydroxides: Synthesis and properties for humidity sensing

In this work, CdAl mixed metal oxides (CdAl-MMOs), CdO/CdAl2O4 composites, were prepared by calcination of sodium dodecyl sulfonate (SDS) intercalated CdAl layered double hydroxide (CdAl-LDH) at different temperature, which was synthesized by traditional hydrothermal synthesis. The CdAl-MMOs were investigated at room temperature, which shows good humidity-sensing performance. Especially, the one calcined at 500 degrees C (CdAlMMO-500) shows good linearity, small hysteresis, high humidity sensitivity as well as satisfactory response and recovery time. In addition, the composites CdO/CdAl2O4 have improved the humidity-sensing performances as compared to the one obtained by calcination of the blending inorganic salts. The experimental results further demonstrate that the approach of calcination LDH precursor can be generalized as an effective way of making mixed metal oxides (MMOs) with homogeneous dispersion between metal elements and thus specific properties.