Ternary ordered assembled piezoelectric composite for self-powered ammonia detection

The sensing performance of gas sensors is determined by three key factors of sensing, transducing and utilization ratio of sensing body. However, these three factors are structurally and functionally independent for most existing gas sensors, restricting the integration and multi-functionalization of the gas discrimination. Herein, we reported a ternary ordered assembly strategy to synchronously and sympatrically integrate and optimize the three key factors in one single device. The in-situ polymerized Ppy coating serves as the sensing component while the embedded PZT nanofiller functions as transducing element, where the utilization ratio of sensing body is directly regulated by the porosity and sensing coating thickness via controlling the sugar granule loading amount and polymerization time. By tuning in-situ polymerization quantity, sacrificial templating amount and transducing loading as well as poling time, an optimal ammonia sensing response was accomplished with a responsivity of 387% at the 100 ppm, a sensitivity of 4.29% ppm−1, excellent selectivity and long-term stability. A theoretical gas-sensitive model was established by combining the experimental characterization with finite element calculation and phase-field simulation. This work throws lights on the fundamental gas sensing mechanism and provides a promising paradigm for developing multi-level controllable sensing devices for physiological assessment and environmental monitoring.