Crystalline Microporous Organosilicates with Reversed Functionalities of Organic and Inorganic Components for Room-Temperature Gas Sensing

Abstract

A deepened investigation on an innovative organic-inorganic hybrid material, referred to as ECS-14 (where ECS = Eni carbon silicates), revealed the possibility to use them as gas sensors. Indeed, among ECS phases, the crystalline state and the hexagonal microplateletlike morphology characteristic of ECS-14 seemed favorable properties to obtain continuous and uniform films. ECS-14 phase was used as functional material in screen-printable compositions and was thus deposited by drop coating for morphological, structural, thermal, and electrical characterizations. Possible operation at room temperature was investigated as technological progress, offering intrinsic safety in sensors working in harsh or industrial environments and avoiding high power consumption of most common sensors based on metal oxide semiconductors. Electrical characterization of the sensors based on ECS-14 versus concentrations of gaseous analytes gave significant results at room temperature in the presence of humidity, thereby demonstrating fundamental properties for a good quality sensor (speed, reversibility, and selectivity) that make them competitive with respect to systems currently in use. Remarkably, we observed functionality reversal of the organic and inorganic components; that is, in contrast to other hybrids, for ECS-14 the functional site has been ascribed to the inorganic phase while the organic component provided structural stability to the material. The sensing mechanism for humidity was also investigated.

Air Stable Nickel-Decorated Black Phosphorus and Its Room-Temperature Chemiresistive Gas Sensor Capabilities

“…As for any new sensing material, the performances of the produced Ni-functionalized bP films were probed through the so-called 3S-rule. , …”

“…As for any new sensing material, the performances of the produced Ni-functionalized bP films were probed through the so-called 3Srule. 45,46 Therefore, experimentation was developed through four steps to investigate the gas sensing performance of Ni/bP-based sensors.…”

Correlation of gaseous emissions to water stress in tomato and maize crops: From field to laboratory and back

“…Then, each sensor was employed inside a circuit, based on an operational amplifier, which collected the variation of the voltage signal that was proportional to the conductance variation of the sensing film. For such system, the sensor response is defined as R=[Ggas-Gair]/Gair, where Ggas is the conductance when the film is exposed to a gaseous compound and Gair is the reference conductance in presence of air [39]. We tested the stability of the sensors employed in this work and we can confirm that their drift is lower than 10% over the period of test [40].…”

“…The sensors signals were collected in continuous for four months, during the whole crops J o u r n a l P r e -p r o o f growing season, by a remote acquisition system. The electronic associated with the in-situ measurement prototypes is the same used in the lab-equipment [39] (Fig. S6, Supporting Information).…”

P2GS.20 - Microporous Organo-Silicates: Functional Hybrid Materials for Room-Temperature Gas Sensing

“…based-sensor showed outstanding performance in humidity conditions and a complete calibration vs. moisture concentration was obtained (see Fig. 1) [6]. ECS-4 and ECS-13 films showed an electrical activity with a low response to benzene and acetaldehyde, respectively [5].…”