Stepwise growth of size-confined CdS in the two-dimensional hydrophilic interlayers of Langmuir–Blodgett films by the repeated sulfidation–intercalation technique

Abstract

When a CdS-bearing stearic acid multilayer produced by exposing a cadmium stearate Langmuir–Blodgett (LB) film to H2S gas is immersed in aqueous CdCl2, Cd ions are intercalated to regenerate the cadmium stearate multilayer without the escape of CdS. The repetition of sulfidation–intercalation cycles allowed the size-quantized CdS to grow in a stepwise fashion in the hydrophilic interlayers. The layered structure was maintained throughout the repeated cycles, although the multilayer-constructing stearate molecules became less oriented by the formation and growth of CdS. The formation of a two-dimensional CdS plane was suggested.