Substituted Zinc Phthalocyanine Based Nanowires for Room Temperature ppb Level Cl2 Sensing Application

Nanowires of substituted Zinc phthalocyanine have been uniformly grown onto glass substrate by cost effective self-assembly technique and their Cl-2 sensing properties have been studied at room temperature in the range 5-1500 ppb. The formation of nanowires is attributed to p-p interactions between the molecules. The density and dimensions of nanowires is found to be dependent upon the concentration of solution. It has been demonstrated that these nanowires are highly sensitive and selective to Cl-2. The nanowires exhibit a response as high as 570% with a fast response time of 15 sec for 1500 ppb of Cl-2 while the minimum detection limit is as low as 5 ppb. XPS studies reveal that predominant sites of interaction of chlorine are central metal ions of substituted zinc phthalocyanine molecules. The studies emphasize their application as low cost room temperature ppb level chlorine gas sensor.