Synthesis of Polypyrrole-zirconia colloidal dispersion for room temperature Ammonia and amine vapors sensing applications

This study reports the synthesis of polypyrrole-zirconia (PPy-ZrO₂) nanocomposites via a one-step chemical oxidative polymerization for high-performance, room-temperature ammonia and amine vapors sensing. The resulting colloidal dispersions exhibited excellent stability (zeta potential: 27 mV) and high electrical conductivity (1.9 S/cm), significantly exceeding pristine ZrO₂. SEM, TEM, and XPS confirmed the formation of uniformly dispersed nanocomposites with strong interfacial interactions. Thermogravimetric analysis (TGA) demonstrated that the incorporation of ZrO₂ nanoparticles significantly enhanced the thermal stability of the PPy matrix. Structural analysis using FTIR, XRD, and Raman spectroscopy confirmed successful hybrid formation and revealed the electronic changes in the polymer backbone upon gas exposure. The PPy-ZrO₂ sensors exhibited high sensing response of 58% towards 100 ppm of ammonia with a fast response time (68 s) and excellent reversibility at room temperature, eliminating the need for external heating. This performance is attributed to the synergistic interfacial charge transfer between the p-type PPy and the n-type ZrO₂ nanoparticles. These findings demonstrate that PPy-ZrO₂ nanocomposites provide a cost-effective and robust solution for stable, room-temperature gas sensing, addressing the limitations of conventional high-temperature sensor technologies. • PPy–ZrO 2 was successfully synthesized, exhibiting excellent dispersion stability and electrical conductivity comparable to pure PPy. • ZrO 2 adsorption on the PPy surface enabled transformation into a more processable form. • PPy–ZrO 2 exhibited distinct resistance changes in response to ammonia and other amine-based gases at room temperature. • Potential application in diode devices and gas sensors for detecting amine-containing gases.