Praveen, L.L.Singh, N.P.Vardhan, R.V.Mandal, S.2026-02-032025Flexible and Printed Electronics, 2025, 10, 1, pp. -https://doi.org/10.1088/2058-8585/adb1f1https://idr.nitk.ac.in/handle/123456789/20385In this work, all-printed tungsten oxide (WO<inf>3</inf>) sensors were fabricated from nanoparticle-based screen-printable inks, where the WO<inf>3</inf> nanopowders were hydrothermally synthesized with various HCl concentrations to give enhanced room-temperature detection of ammonia (NH<inf>3</inf>) gas. The monoclinic phase of WC powders (calcined WO<inf>3</inf>) with square nanoplate-like morphology and porosities was identified from x-ray diffraction, field-emission scanning electron microscopy and Brunauer-Emmett-Teller surface area analysis. The silver precursor ink-derived interdigitated electrodes were found to be crystalline with an average finger width and Ag film thickness of 1 ± 0.4 mm and 3.8 ± 0.5 µm, respectively. The formulated WO<inf>3</inf> inks with hydroxyethyl cellulose showed a thixotropic fluid-like behavior and exhibited a viscosity of ?9 × 104 mPa s, which is a key requirement for screen printing. Rheological study of the formulated WC inks revealed a thixotropic nature, with all WC inks showing a viscosity of 85 ± 3 Pa s and a recovery rate of 80% in the recovery stage. This work explains the role of pH in hydrothermally synthesis of WO<inf>3</inf> by correlating the gas-sensing characteristics of the screen-printed sensors fabricated from formulated inks, where the WC-15 gas sensor showed a maximum gas response of ?340 towards 100 ppm of NH<inf>3</inf> gas. This facile and cost-effective method for fabricating chemiresistive gas sensors could pave the way for the development of flexible and printable devices for ppb-level detection of NH<inf>3</inf> gas and its monitoring. © 2025 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.Cellulose filmsChemical sensorsField emission microscopesGas sensing electrodesInkPhotocompositionScanning probe microscopyScreen printingTungsten sheetX ray powder diffractionAll-printedAmmonia gasGas-sensorsHydrothermalInter-digitated electrodesInterdigitated electrodesNanoplatesNH 3ResponseTungsten oxideAmmoniaDetectionGasRecoverySensorsSilk Screen Printing