Visible light-activated N719-Pd/WO3 heterostructured hollow microspheres for detecting ppb-level triethylamine at low temperature

Triethylamine (TEA) is a kind of flammable and pungent gas, which extensively exists in our daily life. It is paramount important to monitor ppb-level TEA rapidly and selectively at low temperatures. Herein, tungsten oxide hollow microspheres were successfully co-modified by different amount of Pd and N719, and were used to construct semiconductor gas sensor. TEA sensing properties were tested for the N719-Pd/WO 3 and Pd/WO 3 composites under various light illumination conditions. It is exciting to observe that the 0.3 wt% N719-Pd/WO 3 sensor exhibits excellent TEA detectability in terms of ultra-high response (1410, 50 ppm), low operating temperature (100 °C), fast response speed (25 s) and low detection limit (27 ppb) under white light illumination, which are superior to WO 3 sensors loaded with other Pd and N719 concentration as well as upon other light illumination conditions. This excellent sensing performance indicates that the proposed dual-effect improved sensitization by combining noble metal functionalization with visible light excitation offers an effective design for highly sensitive and efficient gas sensors based on wide-band gap semiconductors.