Room Temperature BTX Sensor Based on Zinc Phthalocyanine Thin Film

This study deals with comparing interaction mechanisms of 2(3), 9(10), 16(17), 23(24)-Tetra-((5-bromo-2-methoxyphenyl)diazenyl) phthalocyaninatozinc(II) (zinc phthalocyanine) thin film with versatile chemical vapours: stable and electron donating aromatic vapours namely; benzene, toluene and xylene. The variation in electrical conductivity of zinc phthalocyanine is used as an indicator of the BTX- zinc phthalocyanine interactions. It was found that, unexpectedly, the exposure of the sensor surface to BTX vapors cause an increase in sensor current. It was observed for low concentrations of BTX vapours that, zinc phthalocyanine based sensor exhibits maximum and minimum sensitivities towards toluene and xylene vapors, respectively. However, the maximum and minimum sensitivities of the sensor gradually changes from xylene to benzene for high concentrations of BTX vapors. These findings was concluded in the framework of reaction activation energy and the presence of some water dissociated species, such as H+ or OH−.