Characterization of nano-sized CdS–Ag2S core-shell nanoparticles using XPS technique

Abstract This paper reports the use of X-ray photoelectron spectroscopy (XPS) method for the characterization of surface composition of core and shell nanoparticles. The core and shell nanoparticles were synthesized using sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/n-heptane/water microemulsion technique. The post-core and partial microemulsion methods have shown promise for core and shell formation and enhanced stability and sphericity of the semiconductor nanoparticles. In addition to above technique, the core-shell nanoparticles have also been characterized using SEM-elemental detection X-ray analysis (EDAX) and results are discussed. The XPS studies of CdS, Ag2S, and CdS–Ag2S nanoparticles prepared by post-core/partial microemulsion methods were carried out and results are compared with physical mixing of CdS and Ag2S nanoparticles. The Ag/Cd atomic ratio is found to be 5 and 10 as determined by XPS methods for nanoparticles prepared by using post-core and partial microemulsion methods, respectively. These results show the formation of core and shell nanoparticles.

[1]  장윤희,et al.  Y. , 2003, Industrial and Labor Relations Terms.

[2]  R. Crooks,et al.  Preparation and Characterization of Dendrimer-Encapsulated CdS Semiconductor Quantum Dots , 2000 .

[3]  O. T. Gomez.  [The intern]. , 1957, Revista de la Asociacion Medica Argentina.

[4]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[5]  J. Schneider.  Magnetic Core/Shell and Quantum‐Confined Semiconductor Nanoparticles via Chimie Douce Organometallic Synthesis , 2001 .

[6]  M. Bawendi,et al.  (CdSe)ZnS Core-Shell Quantum Dots - Synthesis and Characterization of a Size Series of Highly Luminescent Nanocrystallites , 1997 .

[7]  T. Mallouk,et al.  Demonstration of a shell-core structure in layered cadmium selenide-zinc selenide small particles by x-ray photoelectron and Auger spectroscopies , 1992 .

[8]  S. Qutubuddin,et al.  Synthesis of titania-coated silica nanoparticles using a nonionic water-in-oil microemulsion , 2001 .

[9]  Y. Qian,et al.  Synthesis of nanocrystalline Ag2S in aqueous solution , 2000 .

[10]  L. Qi,et al.  Synthesis and characterization of mixed CdSZnS nanoparticles in reverse micelles , 1996 .

[11]  M. Stoev,et al.  XPS and XRD study of photoconductive CdS films obtained by a chemical bath deposition process , 1996 .

[12]  Chuan-Jian Zhong,et al.  Core–Shell Assembled Nanoparticles as Catalysts , 2001 .

[13]  Jooho Moon,et al.  Preparation of Ag/SiO2 nanosize composites by a reverse micelle and sol-gel technique , 1999 .

[14]  W. Ji,et al.  LARGE NONLINEAR ABSORPTION IN COATED AG2S/CDS NANOPARTICLES BY INVERSE MICROEMULSION , 1998 .

[15]  L. Motte,et al.  Synthesis in situ of nanosize silver sulphide semiconductor particles in reverse micelles , 1996 .

[16]  Bai Yang,et al.  Synthesis and Optical Properties of CdSe and CdSe/CdS Nanoparticles , 1999 .

[17]  L. Suber,et al.  Size tailoring of CdS nanoparticles by different colloidal chemical techniques , 2001 .

[18]  M. Sastry,et al.  Phase transfer of aqueous CdS nanoparticles by coordination with octadecanethiol molecules present in nonpolar organic solvents , 2000 .

[19]  F. Yubero,et al.  X-ray photoelectron spectroscopy study of the first stages of ZnO growth and nanostructure dependence of the effects of polarization at ZnO/SiO2 and ZnO/Al2O3 interfaces , 2003 .

[20]  Weihong Tan,et al.  Synthesis and Characterization of Silica-Coated Iron Oxide Nanoparticles in Microemulsion: The Effect of Nonionic Surfactants , 2001 .

[21]  T. Hirai,et al.  Immobilization of Semiconductor Nanoparticles Formed in Reverse Micelles into Polyurea via In Situ Polymerization of Diisocyanates , 1998 .

[22]  K. Khilar,et al.  Synthesis of CdS–Ag2S core-shell/composite nanoparticles using AOT/n-heptane/water microemulsions , 2004 .

[23]  H. Monbouquette,et al.  Controlled Synthesis of Mixed Core and Layered (Zn,Cd)S and (Hg,Cd)S Nanocrystals within Phosphatidylcholine Vesicles , 2000 .

[24]  M. Engelhard,et al.  X-ray photoelectron spectroscopic study of the activation of molecularly-linked gold nanoparticle catalysts , 2003 .

[25]  F. Yubero,et al.  Validity of the method for quantitative XPS of surface nano-structures: application to Cu/Au/Cu , 1995 .

[26]  Peng Zhang,et al.  Synthesis and characterization of CdS nanorods via hydrothermal microemulsion , 2003 .

[27]  M. Seah,et al.  Practical Surface Analysis , 1992 .

[28]  J. Toušek,et al.  X-ray photoelectron spectroscopy, scanning electron microscopy and optical transmittance studies of indium tin oxide and cadmium sulphide thin films for solar cells , 1997 .

[29]  Alexander Eychmüller,et al.  Wet Chemical Synthesis of Highly Luminescent HgTe/CdS Core/Shell Nanocrystals** , 2000 .

[30]  S. Asher,et al.  Preparation and Properties of Tailored Morphology, Monodisperse Colloidal Silica-Cadmium Sulfide Nanocomposites , 1994 .

[31]  Younan Xia,et al.  Synthesis and Self-Assembly of Au@SiO2 Core−Shell Colloids , 2002 .

[32]  K. Khilar,et al.  Effects of Intermicellar Exchange Rate on the Formation of Silver Nanoparticles in Reverse Microemulsions of AOT , 2000 .

[33]  M. Pileni,et al.  Copper Metallic Particles Synthesized "in Situ" in Reverse Micelles: Influence of Various Parameters on the Size of the Particles , 1995 .