Construction of Pt/Ce-In2O3 hierarchical microspheres for superior triethylamine detection at low temperature

Abstract

Triethylamine (TEA) is a typical pollution in chemical industry and Corrupt markers of aquatic products. TEA emissions have a serious impact on human health, industrial production and food safety. In this study, hierarchical flower-like Pt-loaded/Ce-doped In2O3 microspheres are synthesized via simple hydrothermal and in-situ reduction methods. The triethylamine (TEA) sensing measurements display the 0.5Pt-3CeIn gas sensor exhibits high sensitivity (Ra/Rg = 900–100 ppm triethylamine), ultra-low optimal working temperature (100 ℃), enhanced responding and recovering speed (158/45 s) and excellent selectivity towards different target gases (ethanol, acetone, xylene, methanol, nitrogen dioxide and methane) including amine (response towards 50 ppm NH3 is lower than 10). The TEA detection limit is as low as 5 ppb and the sensor exhibits a wide TEA detection range. The introduction of Pt and Ce components into In2O3 effectively reduces the operating temperature, promotes the chemisorbed oxygen content (18.14 %) and wildly decreases the band gap (2.97 eV). The gas sensing mechanism of Pt/Ce-In2O3, which is dominated by electronic and chemical sensitization of Pt, catalytic function of Ce dopants and the functional interface between Pt nanoparticles and Ce-doped In2O3 microspheres, is proposed. This work as well testifies the feasibility for multi-components cooperative optimization of MOS in gas sensing applications.