Welding Metallophthalocyanines into Bimetallic Molecular Meshes for Ultrasensitive, Low-Power Chemiresistive Detection of Gases

Abstract

This paper describes the first demonstration of using a series of isoreticular nickel phthalocyanine- and nickel naphthalocyanine-based bimetallic conductive two-dimensional (2D) metal–organic frameworks (MOFs) as active materials in chemiresistive sensing of gases. Devices achieve exceptional sensitivity at sub-part-per-million (ppm) to part-per-billion (ppb) detection limits toward NH3 (0.31–0.33 ppm), H2S (19–32 ppb), and NO (1.0–1.1 ppb) at low driving voltages (0.01–1.0 V) within 1.5 min of exposure. The devices maintain their performance in the presence of humidity (5000 ppm of H2O). The isoreticular analogs enable modular control over selectivity and sensitivity in gas sensing through different combinations of linkers and metal nodes. Electron paramagnetic resonance spectroscopy and X-ray photoelectron spectroscopy studies suggest that the chemiresistive response of the MOFs involves charge transfer interactions triggered by the analytes adsorbed on MOFs.

Synthetic Route to a Triphenylenehexaselenol-Based Metal Organic Framework with Semi-conductive and Glassy Magnetic Properties

“…As bottom-up fabricated solid materials, MOFs with tunable structures and different properties are mainly defined by the two building blocks: metal centers and organic ligands. Up to now, a series of benzene-, triphenylene-, coronene-, or phthalocyaninederived p-conjugated ligands with different donor atoms (O, S, and N) have been employed for the construction of p-d conjugated MOFs with metal bis(dithiolene), metal catecholates, metal bis(diaminoene) and metal bis(aminothiolato) units (Kambe et al, 2013(Kambe et al, , 2014Huang et al, 2015;Pal et al, 2015;Clough et al, 2017;Dong et al, 2018aDong et al, , 2018bSheberla et al, 2014;Dou et al, 2017;Lahiri et al, 2017;Hmadeh et al, 2012;Park et al, 2018a;Meng et al, 2019;Yang et al, 2019;Zhong et al, 2019). Theoretical studies indicate that replacing sulfur by selenium in a hybrid organic-inorganic semiconductor is predicted to decrease the electronic band gap (Stott et al, 2012).…”

A Dual‐Ligand Porous Coordination Polymer Chemiresistor with Modulated Conductivity and Porosity

“…The good linear log–log plots of response versus concentration (Figure b) are consistent with typical chemiresistive behavior. The theoretical limit of detection (LOD) was calculated to be approximately 0.02 ppm using the linear log–log plot and approximately 0.35 ppm using the linear plot by setting the response equal to 3 RMS (RMS=root‐mean‐square deviation) . These values are comparable with the lowest LOD values of room‐temperature chemiresistors reported to date (see Table S4).…”

Strain-based chemical sensing using metal–organic framework nanoparticles

“…Response times of 1-30 s represent an order of magnitude improvement over existing MOF strain-based sensors (see ESI Section S17 †). Sub-ppm sensitivity towards a range of VOCs again represents an improvement in strain-based sensing using MOFs, bringing it on par with hard-to-fabricate photonic crystal thin lms, 56 interdigitated electrode devices [57][58][59] and colorimetric sensors, 60 the latter of which was limited in analyte scope to water. Importantly, we have demonstrated that, in principle, any MOF that can be made in NP form 26 can now be employed in strainbased sensing, which allows for an enormous diversity of chemistries and VOC selectivities.…”