A Comprehensive Review on Polyaniline/Ferrite Nanocomposites for Gas Sensing Applications

The rapid rise of industrialization and urbanization has led to the release of harmful gases into the atmosphere. Commonly used gases, such as liquefied petroleum gas, ethanol, and NO 2 , though essential in homes and laboratories, can pose environmental and safety risks. To address this, ongoing research into gas sensors is crucial for monitoring toxic emissions. Conducting polymers and ferrites have shown great promise in this field. Polyaniline (PANI), a widely studied conducting polymer, is notable for its stability, lightweight nature, and excellent physical, chemical, and electrical properties. Ferrites offer good conductivity and gas sensitivity due to their low density and high surface area. As p‐type (PANI) and n‐type (ferrite) materials, their combination in nanocomposites enhances gas‐sensing performance. PANI/ferrite hybrids offer high sensitivity, selectivity, and stability at room temperature, along with advantages such as low cost, energy efficiency, and good mechanical strength. This review focuses on their synthesis methods, sensing mechanisms, and performance in gas detection at ambient conditions.