High-Performance Ammonia Sensing Electrode Based on a Graphene/Porphyrin–Polyaniline Nanocomposite Material

In view of the hazards and special use value of ammonia (NH₃), the development of various types of sensors sensitive to NH₃ is one of the hot spots in today’s research. Although the conductive polymer polyaniline (PANI) can detect NH₃ at room temperature, it suffers from a series of drawbacks such as low response value, poor selectivity, and long response time. In this study, a graphene/tetraaminophenylporphyrin-PANI (Gr/TAPP-PANI) nanocomposite (GT-P) was prepared by chemical synthesis, and a GT-P NH₃ sensing electrode was constructed by drop-casting deposition. The NH₃ sensing performance of the GT-P sensing electrode was significantly enhanced by optimizing the mass ratio of TAPP to Gr (2:1). At room temperature, the GT-P sensing electrode showed good response to NH₃ with a lower detection limit of 1.99 ppm, high selectivity, and excellent sensing stability. Gr accelerates the electron transfer while π–π stacking with TAPP exposes a larger active center area of TAPP, resulting in the excellent ammonia-sensitive performance of the GT-P sensing electrode. This study provides a strategy for the development of high-performance flexible NH₃ sensors, which has broad application prospects in the fields of environmental monitoring and wearable electronics.