Hybrid materials of carbon nanotubes with fluoroalkyl- and alkyl-substituted zinc phthalocyanines

In this work, hybrid materials of single-walled carbon nanotubes (SWCNT) noncovalently functionalized with fluoroalkyl- (SWCNT/ZnPc-CF) and alkyl- (SWCNT/ZnPc-CH) substituted zinc(II) phthalocyanines were prepared. The effect of fluorination of the substituents in phthalocyanine macrocycle on the functionalization degree of carbon nanotubes and sensor response to ammonia was investigated. It was shown that the type of substituents in the phthalocyanine macrocycle showed noticeable effect both on the degree of functionalization of carbon nanotubes and on the sensing performance of the investigated hybrids. The amount of phthalocyanine molecules adsorbed on SWCNT walls was shown to be 1.5 times higher in the SWCNT/ZnPc-CH hybrid. The SWCNT/ZnPc-CF layer exhibited 2 times less chemiresistive sensor response to ammonia than SWCNT/ZnPc-CH, while its sensor response was more stable at 70% relative humidity.