Layered Double Hydroxide-Based Gas Sensors for VOC Detection at Room Temperature

Abstract

Miniaturized low-cost sensors for volatile organic compounds (VOCs) have the potentiality to become a fundamental tool for indoor and outdoor air quality monitoring, to significantly improve everyday life. Layered double hydroxides (LDHs) belong to the class of anionic clays and are largely employed for NO x detection, while few results are reported on VOCs. In this work, a novel LDH coprecipitation method is proposed. For the first time, a study comparing four LDHs (ZnAl−Cl, ZnFe−Cl, ZnAl− NO 3 , and MgAl−NO 3 ) is carried out to investigate the sensing performances. As explored through several microscopy and spectroscopy analyses, LDHs show a morphology characterized by a large surface area and a three-dimensional hierarchical flowerlike architecture with micro-and nanopores that induce a fast diffusion and highly effective surface interaction of the target gases. The fabricated sensors, operating at room temperature, are able to reversibly and selectively detect acetone, ethanol, ammonia, and chlorine vapors, reaching significant sensing response values up to 6% at 21 °C. The results demonstrate that by changing the LDHs' composition, it is possible to modulate the sensitivity and selectivity of the sensor, helping the discrimination of different analytes, and the consequent integration on a sensor array paves the way for electronic nose development.

Three-dimensional mesoporous ultrathin monometallic cobalt layered double hydroxides nanomaterials as efficient NO2 gas sensor at room temperature

“…[41][42][43] Compared with the other two samples, the larger interlayer spacing of CCM-2 could be conducive to improving its sensing performance. 44 Also, considering the typical low-angle diffraction peak, the characteristic double bands of the ( 110) and ( 113) crystal planes fitted well with previous reports. Also, they indicated the presence of a hydrotalcite-like structure containing interlayer nitrate anions.…”

Recent Advances in Layered Double Hydroxide-Based Electrochemical and Optical Sensors

“…Various spectroscopic methods such as X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), and energy-dispersive X-ray spectroscopy (EDX) elucidate the chemical composition of LDHs. The Brunauer-Emmett-Teller (BET) method characterizes the surface area and porosity of LDHs, which is especially important for gas-sensing LDHs [102][103][104].…”

Modification of pristine layered double hydroxide to form metal oxide composites as an anionic dye photodegradation catalysts

“…In this case, MgPd/Al LDH was as a glycerol hydrogenolysis reaction catalyst [9] and Mg/AlAu LDH was as a nitrophenol hydrogenation catalyst [10]. Other applications in the field of analytical sensors include Cu/Al LDH-graphene as a glyphosate sensor for an aquatic pollutant [11] and Mg/Al LDH as a sensor for volatile organic compounds [12].…”