Effect of TiO2 particle size on the performance of viologen-anchored TiO2 electrochromic device.
The effect of TiO2 particle size on the performance of the electrochromic device (ECD) has been investigated in this work by applying the TiO2 nanoparticles in 7, 15, and 30 nm sizes. The phosphonated viologen, bis(2-phosphonoethyl)-4,4'-bipyridinium dibromide, was anchored on the TiO2 surfaces for the construction of ECD. The ECD derived from 7 nm-sized TiO2 demonstrated the highest contrast ratio with high optical transparency, whereas it showed the slowest switching response. The enhancement of coloration efficiency with decrease of TiO2 particle size is due to the increased amount of the anchored viologen on TiO2 electrode. On the other hand, the relatively slower switching response would be caused by the difficulty of diffusion for the electrolytes and counter-ions through the small pores of the nanocrystalline TiO2 electrode derived from 7 nm-sized nanoparticles.
Kim
Yong Joo
YJ
Department of Chemistry, Inha University, Incheon 402-751, Korea.
Jeong
Hyun Ki
HK
Seo
Jung Kyu
JK
Chai
Seung Yong
SY
Kim
Young Seok
YS
Lim
Goo Il
GI
Cho
Min Ho
MH
Lee
Ik-Mo
IM
Choi
Young S
YS
Lee
Wan In
WI
D003116:Color; D003460:Crystallization / Q000379:methods; D003626:Data Display; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D050866:Liquid Crystals / Q000737:chemistry*; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D010316:Particle Size; D014025:Titanium / Q000737:chemistry*; D014755:Viologens / Q000737:chemistry*
D014755:Viologens; C009495:titanium dioxide; D014025:Titanium