Atomically dispersed Ru on three-dimensionally-ordered macroporous In2O3 for highly sensitive detection of triethylamine and the freshness of seafood

Abstract

As a volatile organic compound, triethylamine (TEA) is extensively employed in industry. Besides, seafood releases gases such as organic amines during the spoilage process, making the detection of TEA of great significance. In this work, three-dimensionally-ordered macroporous (3DOM) indium oxide (In2O3) sensing materials decorated with ruthenium (Ru) dopants were synthesized. The TEA-sensing properties of the Ru/In2O3 were significantly improved than those of the pure In2O3 and the results reported in the literature. Notably, the 0.5Ru/In2O3 sensor had a high response (∼1943) to 50 ppm TEA at 220 °C with good selectivity, long-term stability, and fast response time. In addition, the 0.5Ru/In2O3 sensor had a response value of 14 to a low concentration of 1 ppm TEA. The exceptional TEA-sensing performance was ascribed to the remarkable pore structure of the 3DOM material, facilitating the efficient adsorption and diffusion of TEA. The atomically dispersed Ru increased the amounts of active sites, resulting in enhanced adsorbed oxygen content, reduced activation energy, and improved sensing response. Consequently, incorporating relatively cheap Ru with the 3DOM structure presents a novel approach to enhance the TEA-sensitive performance of metal oxide semiconductor sensors.