Metal-Decorated Phthalocyanine Monolayer as a Potential Gas Sensing Material for Phosgene: A First-Principles Study

Abstract

Research into a gas sensing material with excellent performance to detect or remove toxic phosgene (COCl 2 ) is of great significance to environmental and biological protection. In the present work, the adsorption performance of COCl 2 on pristine phthalocyanine (Pc) and metal-decorated Pc (MePc, Me = Cu, Ga, and Ru) monolayers was studied by first-principles calculations. The results show that the absorption process of COCl 2 on pristine Pc and CuPc both belong to physisorption, indicating that they are not suitable gas sensing materials for COCl 2 . When Pc sheets are decorated by Ga and Ru atoms, the adsorption of COCl 2 is changed into chemisorption, and the corresponding adsorption energies are −0.57 and −0.50 eV for GaPc and RuPc, respectively. The microcosmic mechanism between COCl 2 and adsorbents (GaPc, RuPc) was clarified by the analysis of the density of states, the charge density difference, and the Hirshfeld charge. In addition, the COCl 2 adsorption results in a significant conductivity variation of the RuPc monolayer, demonstrating it exhibits a high sensitivity to the COCl 2 molecule. Meanwhile, quick desorption processes were noticed at various temperatures for the COCl 2 /RuPc system. Consequently, the RuPc monolayer can be considered as a potential candidate for phosgene sensors because of the moderate adsorption strength, high sensitivity, and fast desorption speed.

The Adsorption Mechanisms of SF6-Decomposed Species on Tc- and Ru-Embedded Phthalocyanine Surfaces: A Density Functional Theory Study

“…Moreover, all atoms in the three optimized geometric structures are coplanar. According to our previous investigation [47,48], the hollow site of the H 2 Pc and TMPc monolayer is the preferential adsorption site for the "porphyrin-like" configurations. When the SF 6 decomposition components ap-proach the H 2 Pc/TMPc monolayers, various adsorption styles of SF 6 decomposition gases are considered, as shown in Figure 1d.…”

“…Figure 2 illustrates that the binding energy (E bin ) of RuPc is smaller than the cohesive energy (E coh ) of bulk Ru, indicating robust thermal stability in the RuPc monolayer [47]. Despite TcPc having a larger E bin than the E coh of bulk Tc, the negative value of the binding energy is sufficient to maintain the structural stability of the TcPc monolayer [48]. The high stability of both the RuPc and TcPc monolayers is further supported by an ab initio molecular dynamics (AIMD) simulation, as depicted in Figure 3.…”

Modeling of Close-Packed Patterns of Intact and Partially Deprotonated TPTC Molecules

“…Supramolecular self-assembly on metallic and graphite surfaces has attracted considerable interest in the last two decades. , Through rigorous selection of functional end groups, adaptation of symmetry and dimensions of organic ligands, as well as development of advanced synthesis techniques, it has become possible to manipulate the type, strength, and directionality of intermolecular interactions governing the ordering process during supramolecular growth. Emerging potential applications (heterogeneous catalysis, nanoelectronic devices, etc. − ) have further invigorated the studies of new self-assembled molecular arrays.…”