Toward Tunable Photonic Nanosheet Sensors: Strong Influence of the Interlayer Cation on the Sensing Characteristics

Abstract

An approach toward intercalant tunable nanosheet-based Fabry-Pérot sensors is presented. The intercalant tetrabutylammonium significantly increases the sensitivity of the photonic nose sensor to volatile organic compounds with increasing polarity, enabling polarity-driven color-coded vapor differentiation. Paired with the improved millisecond response times for polar vapors, vapor imaging with spatio-temporal resolution is within reach.

Postsynthetic Doping of MnCl2 Molecules into Preformed CsPbBr3 Perovskite Nanocrystals via a Halide Exchange‐Driven Cation Exchange

“…[15][16][17][18][19][20][21][22][23] However, postsynthetic cation exchange of Pb in perovskite NCs is never reported due to the rigid octahedron structure of Pb cationic sublattice around by six halide anions (PbX 6 4− ). [15][16][17][18][19][20][21][22][23] However, postsynthetic cation exchange of Pb in perovskite NCs is never reported due to the rigid octahedron structure of Pb cationic sublattice around by six halide anions (PbX 6 4− ).…”

“…

structure and diverse morphology. [15][16][17][18][19][20][21][22][23] However, postsynthetic cation exchange of Pb in perovskite NCs is never reported due to the rigid octahedron structure of Pb cationic sublattice around by six halide anions (PbX 6 4− ). [24] Herein, we aimed to achieve partial cation exchange of Pb in perovskite NCs by Mn via a novel way of halide exchange-driven cation exchange (HEDCE).

…”

Photocatalytic Nanosheet Lithography: Photolithography based on Organically Modified Photoactive 2D Nanosheets

“…[13] Tu ning the intrinsic polarity of the nanosheets by partial ion exchange of protons with TBA + therefore enables color-coded polarity differentiation of organic vapors in af ashion similar to the phosphate-based sensors developed by us previously. [13,15] In the next step we combine the enhanced solvent accessibility of the TBA-modified nanosheets with their inherent photoactivity to establish an ew 2D platform for photocatalytic patterning. Photodegradation of TBA + by calcium niobate under UV irradiation is ascribed to the light-induced generation of reactive oxygen species,e specially superoxide radicals,w hich react with TBAu nder H abstraction to form H 2 O 2 .…”

“…[13] This similarity points to the important role of the interlayer cation TBA + ,w hich dominates the overall sensing behavior, rather than the host material itself:T BA acts as ag atekeeper for the swelling process in that it increases the interlayer distance,r endering the diffusion of larger molecules into the intergallery space more facile.I na ddition, it slightly hydrophobizes the interlayer space,m aking the intercalation of moderately polar or unpolar molecules more favorable.Atthe same time, the TBAcations easily hydrate,thus extending the sensitivity range towards both polar and non-polar solvents and enhancing the overall swellability of the system (Figure 2b). [13] Tu ning the intrinsic polarity of the nanosheets by partial ion exchange of protons with TBA + therefore enables color-coded polarity differentiation of organic vapors in af ashion similar to the phosphate-based sensors developed by us previously. [13,15] In the next step we combine the enhanced solvent accessibility of the TBA-modified nanosheets with their inherent photoactivity to establish an ew 2D platform for photocatalytic patterning.…”

“…[7] Theo rganically modified nanosheets exhibit ah eight of 2.6 nm ( Figure 1a), which is in agreement with the XRD measurements (see below) and other data from the literature. [7] Then anosheets were spincoated into optically homogenous films on silicon substrates as depicted in Figure 1b.N ote that the color of the Fabry-PØrot thin films originates from interference,because the film has an optical thickness in the range of half of the wavelength of visible light, [13] according to Equation…”