Detection of Toxic Gases and Volatile Organic Compounds Using Highly Adsorptive Nanomaterials: A Comprehensive Assessment

Abstract

This review presents a comprehensive assessment of highly adsorptive nanomaterials for detecting toxic gases and volatile organic compounds (VOCs). Due to the high surface area-to-volume ratio and tunable properties of nanomaterials, their integration into sensing applications offers superior selectivity and sensitivity for trace amounts of toxic gases or VOCs. The article details the major mechanisms of sensor operation, including chemiresistor electrochemical, catalytic, optical, and field-effect transistor (FET) devices. It then essentially assesses four key nanomaterial categories: carbon-based nanomaterials (e.g., carbon black,graphene oxide, carbon nanotubes, graphene, fullerene, carbon nanofiber, and carbon quantum dots), transition metal oxides (e.g., ZnO, SnO₂, TiO₂, and perovskites), two-dimensional materials (e.g., MoS₂, germanene, and bismuthine), and zeolite-based nanoparticles. For each class, synthesis, functionalization, composites and specific gas sensing performance are discussed, supported by current research. A bibliometric analysis illustrates trends and global collaboration in this field of research. Finally, the review identifies current challenges, including cross-sensitivity and selectivity limitations, long-term stability, and recovery issues, and suggests forward-looking strategies such as machine learning, IoT integration, flexible platforms, and heterojunction engineering to develop real-world sensor applications.