Synthesis of composite gold/tin-oxide nanoparticles by nano-soldering
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- Bajaj, G. & Soni, R.K. J Nanopart Res (2010) 12: 2597. doi:10.1007/s11051-009-9836-2
Composite Au–SnO2 nanoparticles (NPs) are synthesized by nano-soldering of pure Au and SnO2 NPs. The multi-step process involves synthesis of pure Au and SnO2 NPs separately by nanosecond pulse laser ablation of pure gold and pure tin targets in deionized water and post-ablation laser heating of mixed solution of Au colloidal and SnO2 colloidal to form nanocomposite. Transmission Electron Microscopy (TEM) and High-Resolution Transmission Electron Microscopy (HRTEM) were used to study the effect of laser irradiation time on morphology of the composite Au–SnO2 NPs. The spherical particles of 4 nm mean size were obtained for 5 min of post-laser heating. Increased mean size and elongated particles were observed on further laser heating. UV–vis spectra of Au–SnO2 nanocomposites show red shift in the plasmon resonance absorption peak and line shape broadening with respect to pure Au NPs. The negative binding energy shift of Au 4f7/2 peak observed in X-ray Photoelectron Spectra (XPS) indicates charge transfer in the nano-soldered Au–SnO2 between gold and tin oxide and formation of soldered nanocomposite.