Zinc(II)porphyrin-poly(lactic acid) nanoporous fiber membrane for ammonia gas detection

A functional zinc(II)porphyrin-poly(lactic acid) nanoporous fiber membrane (Zn(II)TPP-PLA NFM) for ammonia (NH3) gas detection was developed via the one-step electrospinning method. With the porous structure, Zn(II)TPP-PLA NFM overcomes the limited gas absorption and diffusion of the sensing materials and thus is beneficial to NH3 gas detection. FE-SEM and FT-IR were employed to characterize the morphology and structure of the Zn(II)TPP-PLA NFM. NH3 gas sensing properties of the Zn(II)TPP-PLA NFM were studied by UV-visible spectroscopic techniques. Results showed the Zn(II)TPP-PLA NFM with the volume ratio of dichloromethane/tetrahydrofuran (DCM/THF) 4/1 has a relatively higher porosity of 38 % and the Zn(II)TPP-PLA NFM with 2.0 mg mL(-1) Zn(II)TPP content exhibits an excellent response/recovery performance toward sub-ppm levels of NH3 gas. The detection limit was found to be 0.264 ppm toward NH3 at room temperature. In addition, the performance of this sensor was highly stable after five cycles of tracing NH3 gas and recovery.