A Hybrid Nanomaterial Based on Single Walled Carbon Nanotubes Cross-Linked via Axially Substituted Silicon (IV) Phthalocyanine for Chemiresistive Sensors

Abstract

In this work, the novel hybrid nanomaterial SWCNT/SiPc made of single walled carbon nanotubes (SWCNT) cross-linked via axially substituted silicon (IV) phthalocyanine (SiPc) was studied as the active layer of chemiresistive layers for the detection of ammonia and hydrogen. SWCNT/SiPc is the first example of a carbon-based nanomaterial in which an axially substituted phthalocyanine derivative is used as a linker. The prepared hybrid material was characterized by spectroscopic methods, thermogravimetry, scanning and transmission electron microscopies. The layers of the prepared hybrid were tested as sensors toward ammonia and hydrogen by a chemiresistive method at different temperatures and relative humidity as well as in the presence of interfering gases like carbon dioxide, hydrogen sulfide and volatile organic vapors. The hybrid layers exhibited the completely reversible sensor response to both gases at room temperature; the recovery time was 100–200 s for NH3 and 50–120 s in the case of H2 depending on the gas concentrations. At the relative humidity (RH) of 20%, the sensor response was almost the same as that measured at RH 5%, whereas the further increase of RH led to its 2–3 fold decrease. It was demonstrated that the SWCNT/SiPc layers can be successfully used for the detection of both NH3 and H2 in the presence of CO2. On the contrary, H2S was found to be an interfering gas for the NH3 detection.

Resistive Chemosensors for the Detection of CO Based on Conducting Polymers and Carbon Nanocomposites: A Review

“…Carbon nanomaterials, such as single-walled carbon nanotubes (SWCNTs), pristine carbon nanomaterials, multi-walled carbon nanotubes (MWCNTs), and graphene, have been extensively used as the active layers for the development of chemoresistive sensors [ 5 , 6 , 7 ]. This shift in material usage has been motivated by Kong et al, who observed a change in the conductivity of carbon nanotube (CNT) functionalized materials on gas absorption, leading to their use in a range of gas sensors [ 8 , 9 ].…”

Recent Advances in Ammonia Gas Sensors Based on Carbon Nanomaterials

“…The functionalization of SWCNTs with phthalocyanines made it possible to significantly improve sensing characteristics by means of the covalent or non-covalent functionalization of carbon nanotubes [108]. The cross-sensitivity data presented in [124] showing the significantly higher sensitivity of SWCNT/substituted silicon (IV) phthalocyanine sensors to volatile organic compounds (VOCs) and CO2 make them attractive for the analysis of exhaled breath. In [107], it was found that SWCNTs covalently function-…”

“…The functionalization of SWCNTs with phthalocyanines made it possible to significantly improve sensing characteristics by means of the covalent or non-covalent functionalization of carbon nanotubes [ 108 ]. The cross-sensitivity data presented in [ 124 ] showing the significantly higher sensitivity of SWCNT/substituted silicon (IV) phthalocyanine sensors to volatile organic compounds (VOCs) and CO 2 make them attractive for the analysis of exhaled breath. In [ 107 ], it was found that SWCNTs covalently functionalized with 1-[N-(2-ethoxyethyl)-4-pentynamide]-8(11),15(18),22(25)-tris-{2-[2-(2-ethoxyethoxy)ethoxy]-1-[2-((2-ethoxy ethoxy)-eth-oxy)methyl]ethyloxy}zinc(II) phthalocyanine (ZnPc) possessed higher responsiveness that non-covalently functionalized SWCNTs, which was in correlation with the number of ZnPc molecules adsorbed.…”

Hybrid Materials Based on Carbon Nanotubes and Polyaromatic Molecules: Methods of Functionalization and Sensor Properties

“…In a series of our research group, 3D hybrid materials based on SWCNTs and various polyaromatic linking molecules, viz. pyrene, [74] coumarin, [75,76] BODIPY, [77] and silicon phthalocyanine, [78] were prepared and studied. The hybrids were synthesized according to the well-known reaction of "click chemistry", namely azide-alkyne Huisgen cycloaddition (Figure 9).…”