Enhancing the gas detection capability of materials by regulating defect surface engineering is an effective strategy. In this study, oxygen-deficient tungsten oxide (WO3-x) was prepared by defect engineering by using a heating treatment method. Then the H2 gas sensing performance of WO3-x was explored. Compared to the W18O49 treated at 200, 350, and 400 °C, W18O49 calcined at 300 °C exhibited the highest response (Ra/Rg=1.3). And the response recovery time of the sensor-based on 3W18O49 to 500 ppm H2 is 8 and 13 s, respectively, at 110 °C. Demonstrated by XPS, EPR, PL, EIS, and BET, the presence of oxygen defects enhances the oxygen vacancies and specific surface area, and the coordination number of chemical bond cleavage decreases. The oxygen defect engineering promotes the adsorption, desorption, and charge transport ability of the sensing material to gas molecules. Therefore, this strategy provides an effective method for tungsten oxide sensors for low-temperature H2 detection.
