Preparation of inorganic nanoparticles in oil-in-water microemulsions: A soft and versatile approach

摘要

In this review, the synthesis of inorganic nanoparticles using oil-in-water (O/W) microemulsions as confined reaction media is discussed. Synthesis using (O/W) microemulsions has been demonstrated for a great variety of inorganic nanoparticles: metallic (Pt, Pd, Rh, Ag), single metal oxides (CeO2, ZrO2, TiO2, Fe2O3), mixed and doped metal oxides (Ce_(0.5)Zr_(0.5)O2, Ce_(0.99)Eu_(0.01)O2, Zr_(0.99)Eu_(0.01)O2, and Fe2Mn_(0.5)Zn_(0.5)O4), semiconductors (PbS, CdS, Ag2S, ZnS, CdSe, PbSe, Ag2Se), fluorides (CaF2, YF3, NdF3, PrF3), phosphates (CePO4, HOPO4), and chromates (BaCrO4 and PbCrO4). There are two synthetic strategies: I) the use of oil-in water (O/W) microemulsions, in which the precursor is an ionic salt which is dissolved in the continuous aqueous phase; and 2) use of O/W microemulsions, in which the precursor is an organometallic salt dissolved in the oil droplets of the microemulsion. The latter approach keeps more resemblance to the typical W/O microemulsion reaction method, as it has the greatest level of precursor confinement.