Electrogenerated chemiluminescence of CdS spherical assemblies

We report the first observation of electrogenerated chemiluminescence (ECL) from CdS spherical assemblies in both nonaqueous system and aqueous system. The CdS spherical assemblies consist of CdS nanocrystals about 5 nm in diameter. Four ECL peaks were found under cyclic voltammetric conditions. According to the annihilation mechanism and two-equivalent adsorbed surface state theory, the mechanism for ECL peaks was proposed. The morphology of the CdS spherical assemblies is proved to play an important role in maintaining the stability of partial electrogenerated species to generate the ECL light.