Filamentous network structured WO3 as acetone sensor through spray pyrolysis technique with theoretical approach of molecular interaction

Abstract

Acetone detection in industrial settings is important because of its toxicity and volatility. In the present study, we report the preparation of filamentous-network structured tungsten oxide (WO₃) thin films using a simple spray pyrolysis method. Also, demonstrate their application as an acetone sensor. Structural and morphological studies show that increasing the substrate temperature to 400 °C, results high crystalline monoclinic WO₃, with porous filamentous network, favorable for vapor diffusion. The prepared sensor displayed an excellent response towards acetone at 250 °C, with a wide detection range of 1–200 ppm, detection limit of 1 ppm, and response/recovery time of 60/67 s. Selectivity studies in mixed environment confirmed that it preferentially responded to acetone. After 10 h of continuous exposure the sensor exhibited good compositional stability. Density functional theory (DFT) calculations on monoclinic WO₃ (200) plane, supported the experimental results by confirming that acetone adsorption is exothermic and changes the electronic states close to the Fermi level. The single-step, undoped, filamentous-network WO₃ structure enables a wide detection range at 250 °C and demonstrates a scalable, cost-effective platform for acetone level monitoring in plastic industrial environments.