Core-shell TiO2/Ag Nanoparticle Synthesis and Characterization for Conductive Paste

Core-shell TiO2/Ag nanoparticles were synthesized by a modified sol-gel process and the reverse micelle method using acetoxime as a reducing agent in water/dodecylbenzenesulfonic acid (DDBA)/cyclohexane. The structure, shape, and size of the TiO2/Ag nanoparticles were investigated using X-ray diffraction (XRD), UV-visible spectroscopy, scanning electron microscope (SEM), transmission electron microscope (TEM), and thermogravimetric analysis(TGA). The size of TiO2/Ag nano-particles could be controlled by changing the [water]/[DDBA] molar ratio values. The size and the polydispersity of TiO2/Ag nanoparticles increased when the [water]/[DDBA] molar ratio rose. The resultant Ag nanoparticles over the anatase crystal TiO2 nanoparticles exhibited a strong surface plasmon resonance (SPR) peak at about 430 nm. The SPR peak shifted to the red side with the increase in nanoparticle size. Conductive pastes with 70 wt% TiO2/Ag nanoparticles were prepared, and the pastes were coated on the PET films using a screen-printing method. The printed paste films of the TiO2/Ag nanoparticles demonstrated greater surface resistance than conventional Ag paste in the range of 405 similar to 630 mu Omega/sq