Low-temperature and high-efficient detection of triethylamine based on Pt/PtO2 loaded WO3 gas sensors

Abstract

Triethylamine (TEA) is a kind of flammable and pungent gas, which widely exists in our daily life. It is very important to monitor TEA gas rapidly and selectively at low temperatures. In this work, hierarchical structured WO3 nanomaterials assembled from two-dimensional rectangular nanoflakes were prepared by a simple solvothermal method. On this basis, TEA gas sensors were fabricated successfully by applying different amounts of noble metal Pt on WO3. The results showed that the sensing behavior of WO3 loaded with 1 at% Pt/PtO2 was remarkably improved (3323.5–50 ppm TEA, 137.5 °C) about 90 times than pure WO3 (37–50 ppm TEA, 225 °C), and the response time was shortened to 16 s (pure WO3 was 40 s). In addition, the selectivity of the sensor to TEA was excellent, as well as good repeatability and long-term stability. The improvement of gas sensing performance can be attributed to the catalytic spillover effect of Pt/PtO2, and the existence of heterojunction between PtO2 and WO3, etc. Moreover, density functional theory calculations were used to explain the excellent selectivity of WO3 for TEA. This work provides a new idea for real-time and accurate detection of TEA at low temperatures.