Zn-Modified TiO 2 Thin-Films for Real-Time Formaldehyde Sensing at Room Temperature

This study explores the fabrication and application of zinc-modified titanium dioxide (Zn-TiO 2 ) thin-films for real-time recognition of volatile organic compounds (VOCs), with a particular emphasis on formaldehyde (HCHO) sensing at room temperature. The Zn-TiO 2 thin-films were produced using an economical spray-pyrolysis method. Structural, morphological, and optical characterizations confirmed the successful integration of zinc with varied Wt% (0, 2, 4, and 6) into the TiO 2 lattice. The real-time monitoring capabilities of the sensors were assessed against a range of VOCs, highlighting its specificity for formaldehyde detection amidst diverse environmental constituents. The fabricated thin film sensors with zinc dopant were optimized to enhance the sensor’s performance. 4 Wt% Zn-TiO 2 demonstrated excellent sensitivity to formaldehyde vapor at ambient conditions, showcasing a rapid and selective response. The underlying sensing mechanism was explored, emphasizing the role of zinc doping in tailoring the material’s surface properties and facilitating enhanced adsorption of formaldehyde molecules. The study underscores the potential of Zn-modified TiO 2 thin films as a reliable and efficient platform for real-time VOC monitoring, with a specific focus on HCHO sensing at room-temperature. The sensor shows remarkable stability and repeatability, making it a promising candidate for continuous monitoring applications. Zn-doped TiO 2 thin films are synthesized using the spray pyrolysis method under ambient air conditions, with varying Zn concentrations by weight. The surface, characterized by significant chemisorption and optimal roughness, facilitates an increased number of active sites, leading to enhanced sensor performance. Zn-TiO 2 thin films demonstrate a notable sensor response, achieving a sensitivity of 13.8 at 25 ppm concentration of formaldehyde at room temperature. Demonstrates high potential for integration into advanced sensor technology applications.