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.