Ultraefficient Ammonia Gas Sensors Based on Pt‐Loaded WO3 Nanobars

Herein, unloaded WO 3 (WO 3 ) and Pt‐loaded WO 3 (Pt‐WO 3 ) nanobars are successfully synthesized through simple hydrothermal and impregnation methods. X‐ray diffractometer analysis confirms the formation of a monoclinic WO 3 structure. Surface analysis reveals that the Pt impregnation results in a significant increase in the specific surface area of WO 3 nanobars. The gas‐sensing performance of sensors based on nanobars is measured toward ammonia (NH 3 ) with varying NH 3 concentrations at different operating temperatures. Compared with the pristine WO 3 sensor, the Pt‐WO 3 ‐based sensor with an optimal Pt content of 1 wt% exhibits a relatively low optimum operating temperature of 250 °C and a superior response of 960–50 ppm NH 3 . Furthermore, the Pt‐WO 3 ‐based sensor also displays fast response, excellent NH 3 selectivity to ammonia, moderate humidity dependence, and good stability. Therefore, the developed hydrothermal and impregnation methods could be a suitable alternative procedure for the synthesis of Pt‐WO 3 nanobars useful for advanced NH 3 ‐sensing applications.