Enhancing Structural Integrity, Optical Properties, and Room Temperature Formaldehyde Sensing Through Optimized Spray Deposition Rates

Abstract

This study explores the impact of deposition rate on the properties of TiO2 thin films produced via spray pyrolysis, focusing on their application in gas sensors. The analysis covers structural, morphological, optical, and gas sensing characteristics of TiO2 films deposited at rates between 1 and 2.5 ml min−1. Studies show optimizing TiO2 film deposition rates at 2 ml min−1 significantly enhances formaldehyde detection, improving selectivity and achieving a rapid response of 7.52 at 20 ppm concentration. This study underscores the pivotal role of deposition rate optimization in augmenting the gas-sensing efficacy of TiO2 films, particularly for formaldehyde detection at ambient conditions. Optimal deposition rates are instrumental in enhancing sensor performance. The synergistic application of XRD and Raman spectroscopy unequivocally confirmed the presence of the TiO2 anatase phase, which is of paramount significance in gas sensing applications. FESEM furnished high-resolution insights into the surface morphology, revealing a spherical architecture. Furthermore, UV–vis spectroscopy was employed to assess the optical band gap of the films, which exhibited a decrement correlating with the rate of deposition. Notably, a deposition rate of 2 ml min−1 markedly improved the TiO2 films’ sensing performance. These insights are critical for developing cost-effective, high-performance gas sensors for cutting-edge applications.