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.
Department of Chemistry, Inha University, Incheon 402-751, Korea.
Yong Joo
YJ
Kim
Hyun Ki
HK
Jeong
Jung Kyu
JK
Seo
Seung Yong
SY
Chai
Young Seok
YS
Kim
Goo Il
GI
Lim
Min Ho
MH
Cho
Ik-Mo
IM
Lee
Young S
YS
Choi
Wan In
WI
Lee
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