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This work investigated the sensitivity toward humidity,NO_2 and H_2 of Zn O modified sepiolite(Si_(12)Mg_8O_(30)(OH)_4.(H_2O)_4·8H_2O).To this aim,sepiolite powder was first modified by leaching magnesium ions in HCl then by precipitating nano-sized Zn-based compounds under basic conditions.A subsequent thermal treatment at 550°C for 1 h was performed.The powders were characterized by X-ray diffraction(XRD),specific surface area measurements,thermogravimetric and differential thermal analysis and field emission scanning electron microscopy,as well as high resolution transmission electron microscopy.The XRD patterns showed that all leached heat treated samples were made of anhydrous sepiolite and of Zn O.Sensors were then obtained by screen printing these materials onto commercial alumina substrates with Pt electrodes.All the investigated compositions were capable of detecting NO_2 down to ppm level and 20 ppm H_2,at an optimal working temperature of 300°C.These detection limits are in line with the current best results reported in literature.
This work investigated the sensitivity toward humidity, NO_2 and H_2 of Zn O modified sepiolite (Si_ (12) Mg_8O_ (30) (OH) _4. (H_2O) _4 · 8H_2O) .To this aim, sepiolite powder was first modified by leaching magnesium ions in HCl then precipitated nano-sized Zn-based compounds under basic conditions. A subsequent thermal treatment at 550 ° C for 1 h was performed. The powders were characterized by X-ray diffraction (XRD), specific surface area measurements, thermogravimetric and differential thermal analysis and field emission scanning electron microscopy, as well as high resolution transmission electron microscopy. XRD patterns showed that all leached heat treated samples were made of anhydrous sepiolite and of Zn O.Sensors were then obtained by screen printing these materials onto commercial alumina substrates with Pt electrodes. All the compositions compositions capable of detecting NO_2 down to ppm level and 20 ppm H_2, at an optimal working temperature of 300 ° C. These detection limits are in line with the current best results reported in literature.