Transition Metals Doped Nanocrystals: Synthesis, Characterization, and Applications

Doping is a technique that makes it possible to incorporate substitutional ions into the crystalline structure of materials, generating exciting properties. This book chapter will comment on the transition metals (TM) doped nanocrystals (NCs) and how doping and concentration influence applications and biocompatibility. In the NCs doped with TM, there is a strong interaction of sp-d exchange between the NCs’ charge carriers and the unpaired electrons of the MT, generating new and exciting properties. These doped NCs can be nanopowders or be embedded in glass matrices, depending on the application of interest. Therefore, we show the group results of synthesis, characterization, and applications of iron or copper-doped ZnO nanopowders and chromium-doped Bi2S3, nickel-doped ZnTe, and manganese-doped CdTe quantum dots in the glass matrices

Electrochemical oxidation of p -chlorophenol on SnO2–Sb2O5 based anodes for wastewater treatment

The influence of an IrO2 interlayer between the Ti substrate and the SnO2-Sb2O5 coating on the electrode service life and on the efficiency of p-chlorophenol (p-CP) oxidn. for wastewater treatment has been investigated. The results have shown that if the loading of the SnO2-Sb2O5 coating relative to the IrO2 interlayer loading (g ratio defined by Equation 1) is high (g = 20-30) the service life of the electrode can be increased without modification of the ability of this electrode to perform p-CP oxidn. This suggests that the oxidn. of p-CP using a Ti/IrO2/SnO2-Sb2O5 electrode with high g ratio (g > 20) occurs only through the SnO2-Sb2O5 component of the electrode, with no interference of the IrO2 interlayer. However, the electrode potential at a given c.d. is considerably lower in the case of the Ti/IrO2/SnO2-Sb2O5 electrode. In order to explain this decrease in electrode potential we speculate that water is firstly discharged on IrO2, which is present in small amts. on the surface, forming hydroxyl radicals at a relatively low potential. These active hydroxyl radicals then migrate (spill over) towards the SnO2-Sb2O5 coating, where they are physiosorbed and react with p-CP leading to complete combustion