Innovative method to avoid the reduction of silver ions to silver nanoparticles ( A g⁺→ Ag^∘ ) in silver ion conducting based polymer electrolytes

In this research work an innovative method is used to prevent the silver ion reduction in solid polymer electrolytes. The x-ray diffraction (XRD) results reveal the disruption of the crystalline nature of chitosan (CS) and formation of silver nanoparticles upon addition of silver triflate (AgTf) salt. The UV-vis measurement confirms the existence of silver nanoparticles via the broad surface plasmon resonance (SPR) peak. Upon the addition of Al 2 O 3 nanoparticles the SPR peak intensity is greatly reduced. The amorphous domain of the CS:silver triflate (CS:AgTf) system increases with the addition of Al 2 O 3 nanoparticles up to 4 wt.%. Deconvolution of the XRD results reveals that a larger crystallite size is obtained for higher Al 2 O 3 concentrations and the peaks due to silver nanoparticles almost disappear. Scanning electron microscope (SEM) analyses show that Al 2 O 3 nanoparticles are well dispersed at low concentrations and the leakage of chains of silver nanoparticles to the membrane surface almost disappear. The XRD, UV-vis, SEM and energy-dispersive x - ray (EDX) results strongly support that the reduction of silver ions to silver nanoparticles (Ag + → Ag°) in the CS:silver triflate system is significantly avoided upon the addition of an Al 2 O 3 filler.