Ultraefficient Ammonia Gas Sensors Based on Pt‐Loaded WO₃ Nanobars

Abstract

Herein, unloaded WO3 (WO3) and Pt‐loaded WO3 (Pt‐WO3) nanobars are successfully synthesized through simple hydrothermal and impregnation methods. X‐ray diffractometer analysis confirms the formation of a monoclinic WO3 structure. Surface analysis reveals that the Pt impregnation results in a significant increase in the specific surface area of WO3 nanobars. The gas‐sensing performance of sensors based on nanobars is measured toward ammonia (NH3) with varying NH3 concentrations at different operating temperatures. Compared with the pristine WO3 sensor, the Pt‐WO3‐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 NH3. Furthermore, the Pt‐WO3‐based sensor also displays fast response, excellent NH3 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‐WO3 nanobars useful for advanced NH3‐sensing applications.