Amine-functionalized stable Nb₂CT_x MXene toward room temperature ultrasensitive NO₂ gas sensor

Abstract

Large surface area and abundant surface functional groups favor the MXene (Nb2CTx) for potential gas sensor applications. However, atmospheric instability is the major limitation of the MXenes. In this work,...

Recent developments in 2D MXene-based materials for next generation room temperature NO2 gas sensors

“…51,91,93–95 Naveen Kumar et al found that covalently modifying MXenes (Nb 2 CT x ) with (3-aminopropyl)triethoxysilane (APTES) via silylation molecules increased the stability and allowed for the simultaneous inclusion of extra reactive NH 2 group. 65 The APTES reduces the MXene oxidation by producing a homogenous, thick protective layer over the surface of Nb 2 CT x . APTES served as an electron acceptor, facilitating electron transfer to NO 2 molecules via MXenes.…”

“…example, Naveen Kumar et al demonstrated that the introduction of amine groups over the Nb 2 CT x MXene helps in the detection of acidic gases such as NO 2 by acting as an electron acceptor 65. Rathi et al also modied Nb 2 CT x MXene with CTAB and here the stability enhancement was ascribed to the (i) noncovalent bonding between CTAB and Nb 2 CT x MXene (ii) the long hydrophobic chains in CTAB hinders the interaction of humidity and oxygen with Nb 2 CT x MXene.…”

MXene-based highly sensitive and selective NH3 sensor

“…MXenes can be easily synthesized from their parent bulk MAX phase (A being Al, Si or Ge) by selective etching of A element [3][4][5]. MXenes are highly useful for the detection of toxic gases due to fascinating properties like high surface-to-volume ratio resulting into abundance of gas adsorption sites, metallic conductivity, high signal-to-noise ratio, rich elemental composition and surface terminal groups, mechanical strength and flexibility, and strong hydrophobicity [6,7]. Among MXenes, Ti3C2Tx has been widely explored for gas sensing applications due to its conductive nature [8,9].…”

Amine-Functionalized Black Phosphorus Nanosheets toward Ultrafast and Room-Temperature Trace Carbon Dioxide Sensing

“…28% toward 10 ppm of CO 2 with a mean standard error of 1.9% over 15 days, indicating a decent long-term stability (Figure f). The nice operation robustness probably lay in the presence of the hydrophobic methoxy group within APTES that effectively passivated the reactive sites via direct covering and blocked the external water adsorption within the BP nanosheets . Due to the strong electron-donating property of amine moieties within APTES and p -type property of BP nanosheet, , electrons were spontaneously extracted from APTES to BP, leading to the increase of baseline resistance.…”

“…The nice operation robustness probably lay in the presence of the hydrophobic methoxy group within APTES that effectively passivated the reactive sites via direct covering and blocked the external water adsorption within the BP nanosheets. 19 Due to the strong electron-donating property of amine moieties within APTES and p-type property of BP nanosheet, 20,21 electrons were spontaneously extracted from APTES to BP, leading to the increase of baseline resistance. Note that the direct interplay between BP and analyte gas was scarce as BP was largely covered by viscous APTES.…”