Sensitivity Enhancement of Benzene, Toluene, and Xylene Gas Sensors using Nanostructured TiO2: a Mini-Review

Benzene, toluene, and xylene (BTX) are hazardous volatile organic compounds commonly found in industrial and environmental settings, requiring the development of highly sensitive and selective gas sensors to ensure public safety. Nano-structured titanium dioxide (TiO₂) has emerged as a promising BTX-sensing material due to its high chemical stability, advantageous catalytic properties, and tunable electronic structure. However, material modification is required because of the limited gas sensitivity of pristine TiO₂. This review discusses key strategies for enhancing the BTX-sensing performance of TiO₂-based gas sensors, including nanostructuring, metal doping, metal and metal oxide decoration, thermal treatment, and organic functionalization. These approaches improve gas adsorption, charge-carrier mobility, and reaction kinetics, thus enhancing the response and selectivity of the resulting sensor. The integration of TiO₂ sensors with microheater platforms also enables low-power operation for practical deployment. This review highlights current challenges facing the development of TiO₂-based gas sensors, including sensor stability, crosssensitivity, and real-time monitoring while proposing future directions for these devices.