Diethylbenzene and ethyltoluene adsorption studies on novel beta antimonide phosphorus nanosheets-a first-principle study.

CONTEXT: In the present work, we examined the sensing behavior of monolayer beta antimonide phosphorus (ß-SbP) sheets towards toxic volatile organic compounds (VOCs) namely, 1,2-diethylbenzene and 2-ethyltoluene using density functional theory (DFT) method. At first, using cohesive energy structural stability of the monolayer ß-SbP is confirmed. The calculated energy band gap value of monolayer ß-SbP is 2.168 eV, which is a semiconductor. Furthermore, the adsorption properties of 1,2-diethylbenzene and 2-ethyltoluene on ß-SbP are studied through key factors, such as adsorption energy, Mulliken charge transfer, and relative band gap variation. The adsorption energy clearly shows (- 0.335 to - 0.903 eV) that both 1,2-diethylbenzene and 2-ethyltoluene are physisorbed on ß-SbP monolayer. Besides, Mulliken charge transfer falls in the range of - 0.465 to 0.933 e; this information clearly shows that the ß-SbP monolayer is a potential candidate for sensing 1,2-diethylbenzene and 2-ethyltoluene molecules. METHODS: The structural firmness including electronic and adsorption properties of 1,2-diethylbenzene and 2-ethyltoluene on ß-SbP monolayer are investigated with the support of the DFT method. Particularly, the hybrid generalized gradient approximation (hybrid GGA) along with Beck's three-parameter + Lee-Yang-Parr (B3LYP) exchange-correlation functional is utilized for relaxing the ß-SbP monolayer. In the present work, all calculations are performed using the Quantum Atomistic Tool Kit (ATK) simulation package. In the present work, we utilized ß-SbP monolayer as a chief sensing element to detect 1,2-diethylbenzene and 2-ethyltoluene to safeguard humans from toxic environments.

Novel chair graphene nanotubes as adsorbing medium for alanine and asparagine amino acids - A DFT outlook.

Amino acids are required to make protein. The deficiency of amino acids leads to a lack of sleep and mood. Among various amino acids, we conducted the adsorption studies of alanine and asparagine amino acids on a novel one-dimensional material, chair graphene nanotube. The stability of the chair graphene nanotube is ensured with the negative formation energy, which is -6.490 eV/atom. The energy band gap of bare chair graphene nanotube is 1.022 eV, which possesses a semiconductor nature. The stable chair graphene nanotube is used as adsorbing material for alanine and asparagine amino acids. Besides, alanine and asparagine are physisorbed on chair graphene nanotubes that are confirmed by the range of adsorption energy from -0.107 eV to -0.718 eV. Upon adsorption of amino acids, the charge transfer outcome shows that chair graphene nanotubes behave as donors of electrons to alanine and asparagine. Further, the changes in the band gap of the chair graphene nanotube are noticed from the results of band structure and PDOS spectrum. The changes in the electron density also reveal the changes in the electronic properties of the chair graphene nanotube owing to alanine and asparagine sorption. The proposed report portrays the adsorption attributes of alanine and asparagine amino acids on 1D chair graphene nanotubes.

N-Nitrosamine sensing properties of novel penta-silicane nanosheets-a first-principles outlook.

CONTEXT: N-Nitrosamine is one of the highly toxic carcinogenic compounds that are found almost in the entire environment. In the present work, novel penta-silicene (penta-Si) and penta-silicane (penta-HSi) are utilised to sense the N-nitrosamine in the air environment. Initially, structural firmness of penta-Si and penta-HSi is confirmed using cohesive energy. Subsequently, the electronic properties of penta-Si and penta-HSi are discussed with the aid of electronic band structure and projected density of states (PDOS) maps. The calculated band gap of penta-Si and penta-HSi is 0.251 eV and 3.117 eV, correspondingly. Mainly, the adsorption property of N-nitrosamine on the penta-Si and penta-HSi is studied based on adsorption energy, Mulliken population analysis along with relative energy gap changes. The computed adsorption energy range is in physisorption (- 0.101 to - 0.619 eV), which recommends that the proposed penta-Si and penta-HSi can be employed as a promising sensor to detect the N-nitrosamine in the air environment. METHODS: The structural, electronic and adsorption behaviour of N-nitrosamine on penta-Si and penta-HSi are studied based on the density functional theory (DFT) approach. The hybrid generalized gradient approximation (GGA) with Becke's three-parameter (B3) + Lee-Yang-Parr (LYP) exchange correlation functional is used to optimise the base material. All calculations in the present work are carried out in Quantum-ATK-Atomistic Simulation Software.

Recent progress on the synthesis, properties and applications of antimonene - A mini-review.

The recent advancement in group VA monolayer and few-layer materials leads to fascinating applications. In this mini-review, we present the state-of-the-art in the synthesis of antimonene, its properties and various applications. Besides, the electronic properties of antimonene depend on its allotropes. Furthermore, we studied the electronic properties of δ, ε, and twisted-θ antimonene nanosheets, nanoribbons, and nanoring, and the results are reported. Moreover, the structural stability and electronic properties of antimonene is influenced by its allotrope and nanostructure. The report will give insights into the synthesis, properties, applications, and future outlook of antimonene.

Interaction studies of propylene and butadiene on tricycle graphane nanosheet - A DFT outlook.

In this research work, we employed a tricycle graphane nanosheet as a chemical sensor to monitor the toxic hydrocarbon molecules, namely propylene, and 1,3-butadiene, which are emitted from automobile industries. At first, the structural stability and dynamical permanency of tricycle graphane is ascertained based on cohesive energy and phonon-band-spectrum. Sequentially, the electronic properties of tricycle graphane are conferred with the results of the projected density of states spectrum and band structure. The computed band gap of tricycle graphane is 5.53 eV. Chiefly, the adsorption behaviour of target propylene and 1, 3-butadiene on tricycle graphane is explored by determining adsorption energy, relative band gap variation, and Mulliken population analysis. Furthermore, the range of adsorption energy magnitudes (-0.16 eV to -1.03 eV) demonstrates that the target hydrocarbon molecules are physically adsorbed on tricycle graphane material. The overall outcome endorses that the tricycle graphane can be utilised as a prominent sensor to sense the hydrocarbon molecules released from automobiles and monitor air pollutants.

Adsorption studies of camphene and eucalyptol molecules on orthorhombic germanane nanosheet - A first-principles investigation.

In the present work, we deployed a novel orthorhombic germanane nanosheet (ortho-GeNS) as a sensing material to detect camphene and eucalyptol molecules, the indoor air pollutants in the ambient environment. In the beginning, the structural and dynamical permanency of ortho-GeNS is confirmed with cohesive energy (-4.164eV/atom) and phonon-band maps. Successively, the electronic features of ortho-GeNS are conferred using band structure along with the projected density of states maps. The energy gap of ortho-GeNS at the hybrid GGA/B3LYP level of theory is computed to be 3.948 eV. Mainly, the adsorption properties of terpinene molecules, namely camphene and eucalyptol on ortho-GeNS are investigated via ascertaining adsorption energy, Mulliken population analysis, and relative band gap variations. Besides, the scope of adsorption energy values (-0.405eVto-0.669eV) exemplifies that the target molecules are physisorbed on ortho-GeNS. Overall results suggested that the ortho-GeNS can be deployed as a worthy chemiresistive sensor to sense indoor air pollutants for monitoring indoor air quality.

Physisorption of trichloroethylene and tetrachloroethylene on novel zeta arsenene nanotubes - A first-principles study.

The structural stability of novel ζ-arsenene nanotubes (ζ-AsNT) is studied based on the density functional theory framework and is used as a base material for the detection of trichloroethylene and tetrachloroethylene vapours. The formation energy of ζ-AsNT is found to be -4.321 eV/atom and the energy band gap is 0.304 eV. Besides, the changes in the electronic properties of ζ-AsNT are explored with regard to the projected density of states, charge transfer, and electron density difference. The bandgap energy decreases for hollow site orientation to 0.205 and 0.204 eV for trichloroethylene and tetrachloroethylene vapours and increases for the valley and top site orientations. The adsorption energies were maximum for the valley site orientation of target molecules onto ζ-AsNT (01.165 and -1.513 eV for trichloroethylene and tetrachloroethylene, respectively). Moreover, the target vapours trichloroethylene and tetrachloroethylene are physisorbed on ζ-AsNT enabling the recycling of base substrate for continuous operation. The average energy gap changes vary from 18 to 32.9% depending on adsorption sites. The variation in the average energy gap owing to adsorption of trichloroethylene and tetrachloroethylene indicates the chemo-sensing nature of ζ-AsNT. The current report lays the inroads in the development of a new sensing element for the detection of chloroethylene molecules.

Twisted bilayer arsenene sheets as a chemical sensor for toluene and M-xylene vapours - A DFT investigation.

2D (two-dimensional) materials are emerging in today's world. Among the 2D materials, arsenene sheets are prominently used as chemical and biosensors. In the present work, the twisted bilayer arsenene sheets (TB-AsNS) are used to adsorb toluene and M-xylene vapours. Moreover, the band gap of pristine TB-AsNS is calculated to be 0.437 eV. Besides, the surface adsorption of toluene and M-xylene vapours modify the electronic properties of TB-AsNS noticed from the band structure, density of states, and electron density difference diagrams. The surface assimilation of target toluene and M-xylene on TB-AsNS falls in the physisorption regime facilitating the adsorption and desorption of molecules. Also, the charge transfer analysis infers that TB-AsNS acts as acceptor and target molecules play as donors. The findings support that TB-AsNS can be used as a sensing medium towards M-xylene and toluene.

Zipper phosphorene as sensing element towards formaldehyde and acetaldehyde - A first-principles insight.

We ascertained the structural stability of zipper phosphorene nanosheet (zP-NS) and studied the adsorption behaviour of toxic aldehyde compounds including formaldehyde (FD) and acetaldehyde (AD) on zP-NS based on first-principles calculation. Considerably, zP-NS reveal a semiconducting character with band gap of 1.35 eV. Especially, four distinct favourable adsorption positions including bridge-, hollow-, top- and valley-site of FD and AD vapours on zP-NS were investigated. Furthermore, the calculated binding-energy of prominent adsorption sites are observed to be in the scope of -0.143 eV to -0.411 eV advocating physisorption nature of the interaction of chief aldehydes on zP-NS. The overall outcomes recommend that zP-NS can be persuasively utilised as a chemical sensor for monitoring FD and AD molecules in indoor air environment.

Sorption studies of sulfadimethoxine and tetracycline molecules on ß-antimonene nanotube - A first-principles insight.

We ascertained the structural firmness of ß-antimonene nanotube and studied the adsorption behaviour of sulfadimethoxine (SM) and tetracycline (TC) molecules on the base substrate using density functional theory (DFT) with B86LYP-D3 level of theory. Significantly, ß-antimonene nanotube displays a semiconducting character with an energy band-gap of 0.263 eV. The three dissimilar preferential adsorption sites namely, bride-, hollow-, tube-inner site of SM and TC molecules on ß-antimonene nanotube were investigated using average band gap changes, Bader charge transfer along with adsorption energy. Further, the calculated adsorption energy for preferential adsorption sites is noticed to be in the scope of -0.813 eV to -3.752 eV signifying to physisorption and chemisorption form of interaction on ß-antimonene nanotube. The inclusive outcome recommends that ß-antimonene nanotube can be deployed as a chemi-resistive sensor to sense and remove SM and TC molecules from the contaminated aqueous medium.

Interaction studies of glycine, acetate and methylamine on ß-tellurene nanoribbon - A first-principles analysis.

We investigated the structural stability of ß-tellurene nanoribbon (ß-TeNR) and explored the adsorption behaviour of glycine, acetate, and methylamine malodorous molecules on ß-TeNR based on ab-initio calculations. Besides, ß-TeNR exhibits semiconducting behaviour with a direct energy gap (Eg) of 1.657 eV. In the beginning, the dynamical solidity and geometrical firmness were confirmed with regard to the phonon band spectrum and negative cohesive energy (-3.406 eV/atom), respectively. With the support of band structure and PDOS (projected-density of states), the electronic characteristics of ß-TeNR are explored. Provocatively, two dissimilar superior adsorption sites (top &hollow-sites) of chief malodorous on ß-TeNR were demonstrated with regard to the average band gap variation (Ega), Bader charge transfer (Q), and binding energy (EB). The calculated EB of preferential interaction sites is found to be in the scope of -0.190 to -1.751 eV referring to mixed physisorption and chemisorption type of interaction upon ß-TeNR. The outcomes recommend that ß-TeNR can be positively utilised as a chemi-resistor to sense the glycine, acetate, and methylamine molecules in an unpleasant atmosphere.

Adsorption studies of nucleobases on ε-arsenene nanosheet based on first-principles research.

The electronic attributes and energetics of ε-arsenene nanosheet (ε-As) are explored with regard to the density functional theory basis. Initially, based on formation energy (-3.715 eV/atom), we ensured the structural firmness of ε-As. The ε-As is used as a base substrate to adsorb nucleobases viz., adenine (A), guanine (G), thymine (T), cytosine (C) & uracil (U). The surface adsorption of nucleobases on ε-As is analysed based on band structure, the density of states, adsorption energy, energy gap variation & charge transfer. Besides, we observed the exothermic nature of binding energy (ranging from -0.453 eV to -0.819 eV) upon nucleobase adsorption on ε-As. Also, the energy gap variation & charge transfer takes place owing to adsorption of nucleobases on the ε-As sheet. The present report reveals the adsorption of nucleobases on ε-arsenene nanosheet.

Novel green phosphorene sheets to detect tear gas molecules - A DFT insight.

The green phosphorene (GP) nanosheet, one of the allotropes of layered phosphorene is employed to detect the existence of tear gas molecules. The tear gas molecules such as 1-bromo-2-butanone, bromoacetone, and bromobenzyl cyanide are examined with the service of the ATK-VNL package by employing density functional theory (DFT) method. The geometrical stability of the chief component is affirmed with the support of formation energy and electronic fingerprints of GP nanosheet like electron density, band structure, and projected density of states (PDOS) spectrum are estimated. In this research work, using DFT technique, for the first time, surface adsorption characteristics of the target molecules on GP nanosheet are explored with the assistance of adsorption energy, average energy gap variation, and Bader charge transfer, which further suggest the deployment of GP in sensing the presence of tear gas molecules.

Investigation on adsorption features of nitroglycerin on novel red tricycle arsenene nanosheet - A first-principles study.

The chemo sensing features of red tricycle arsenene nanosheet (RTANS), a monolayer obtained from allotropes of arsenic is employed in sensing the hazardous vapor nitroglycerin (NG) based on the first-principles investigation. The computations are carried out with the ATK-VNL package. The stability of the RTANS is validated by its formation energy, which is calculated as -4.171 eV/atom. The adsorption energy, Bader charge transfer, energy gap, and its variation after adsorption are the essential parameters that hold up the discussion on RTANS base material as an efficient chemical sensor. Moreover, the target vapor NG is physisorbed on RTANS. Besides, all the essential parameters have been investigated for the interaction of NG on RTANS. The comprehensive study reveals that RTANS can be used as a chemical sensor for the detection of nitroglycerin vapors.

Interaction studies of kidney biomarker volatiles on black phosphorene nanoring: A first-principles investigation.

We report the electronic properties of black phosphorene nanoring (BPN) and adsorption behavior of chronic kidney disease biomarker vapors on BPN. The designed BPN is stable, which is ensured by the formation energy with a value of -3.857eV/atom. The band gap of BPN is recorded as 0.716eV showing the semiconductor property. The prominent kidney disease biomarker vapors, namely isoprene, pentanal, hexanal, heptanal are allowed to interact on BPN and studied based on adsorption property on BPN. Based on charge transfer, energy band gap variation and adsorption energy, we studied the adsorption behavior of BPN towards kidney disease biomarkers. Our findings show that BPN can be used to detect the presence of kidney biomarkers.

Exploring adsorption behavior of ethylene dichloride and dibromide vapors on blue phosphorene nanosheets: A first-principles acumens.

The interrelation of toxic vapors ethylene dichloride (EDC) and ethylene dibromide (EDB) with the sensory base material blue phosphorene nanosheet (BLPNS) is studied using ab-initio method. The formational stability of BLPNS is ensured by the negative value of formation energy. Prior to the adsorption studies, we calculated the formation energy of BLPNS to ensure its stability, which is calculated to be -5.194eV/atom and found stable. The main motive behind the present work is to detect these toxic vapors using BLPNS. The intercommunication between the targeted vapors and the base material has been analyzed using the aid of adsorption energy, Bader charge transfer, energy band gap, and variation of band gap along with energy bands and DOS spectrum. The energy gap of isolated BLPNS is observed to be 1.621eV. However, the adsorption of EDC and EDB modulates the energy gap of BLPNS. The nature of assimilation is noticed to be of physisorption, which facilitates desorption of EDC and EDB molecules much easier. The successful outcome of the present research validates that BLPNS can be deployed as a prominent sensor for detection of EDC and EDB effectively.

Nitrogen mustard gas molecules and α-arsenene nanosheet interaction studies - A DFT insight.

Bis(2-chloroethyl)ethylamine (HN-1) and Bis(2-chloroethyl)methylamine (HN-2) are two classifications under the blistering agents, which are taken as target nitrogen mustard gas in the current research. α-arsenene nanosheets in its puckered configuration, are employed as a prime material to detect the above mentioned gas molecules. The chemo-sensing nature of the base material towards the target gas is ascertained with the assistance of electronic and surface assimilating attributes with the help of density functional theory technique. Initially, the geometric firmness of the base material is ensured with formation energy, which was computed to be -4.262 eV/atom, and we studied the electronic properties like the density of states spectrum, band structure, and electron density. Furthermore, surface assimilating attributes like Bader charge transfer, adsorption energy, average energy gap variation are estimated at atomistic levels using ATK-VNL package. The adsorption of nitrogen mustard gas molecules on α-arsenene nanosheets shows physisorption type of binding. The average energy gap variation of α-arsenene nanosheets upon adsorption of nitrogen mustard gas molecules ranges from 1.33 to 4.1%. Hence, the results suggest that α-arsenene nanosheets can be used as a chemical nanosensor for nitrogen mustard gas.

Perceptions on the adsorption of COPD biomarker vapors on violet phosphorene nanosheet - A first-principles study.

We systematically investigated the adsorption characteristics of chronic obstructive pulmonary disease (COPD) biomarker volatiles on violet phosphorene with density functional theory approach. The formation energy of violet phosphorene indicates its stable structure. The electronic properties of violet phosphorene credit that it is a suitable material for biosensors. We explored the adsorption mechanism of hexanal and nonanal molecules based on electron density variation, the density of states (DOS) spectrum, band structure analysis of violet phosphorene. The results of adsorption energy, charge transfer also strengthen that COPD volatile organic compounds can be adsorbed on violet phosphorene. The proposed report strongly values that violet phosphorene as a prominent candidate to identify the biomarkers in COPD patients from the exhaled breath.

Exploring adsorption mechanism of hydrogen cyanide and cyanogen chloride molecules on arsenene nanoribbon from first-principles.

The SIESTA package is employed in examining the electronic and adsorption features of the toxic asphyxiants hydrogen cyanide (HCN) and cyanogen chloride (NCCl) on armchair arsenene (As-arm) nanoribbon. Based on the generalized gradient approximation (GGA) with the Perdew-Burke-Ernzerhof (PBE) level of theory, we explored the adsorption of HCN and NCCl on As-arm nanoribbon. The significant parameters necessary to validate the electronic and stable nature of As-arm nanoribbon are computed with the help of formation energy and energy gap change. The density of states (DOS) spectrum and the energy band structure are figured-out for both isolated and asphyxiants adsorbed As-arm nanoribbon, which affirms the transfer of electrons taking place between As-arm nanoribbon and the asphyxiants. Also, surface assimilating properties like Bader charge transfer, average energy gap variation, and adsorption energy are calculated for the asphyxiants adsorbed As-arm nanoribbon. Moreover, the comparison is made between the electron density of isolated and asphyxiants adsorbed As-arm nanoribbon to enunciate the utilization of As-arm nanoribbon as a chemisensor for detecting the asphyxiants HCN and NCCl molecules.

Detection of trace level of hazardous phosgene gas on antimonene nanotube based on first-principles method.

Using first-principles calculations, electronic characteristics and geometrical stability of pure and Sn substituted armchair ß - antimonene nanotube (SbNT) is explored. The adsorption behavior of phosgene (COCl2) on SbNT is studied using ab initio method. Also, the effect of base material sensitivity with the influence of substitution of Sn dopant is studied. The SbNT energy band structure gets altered upon exposure to the COCl2 gas molecules. The density-of-states (DOS) spectrum gives the precision on the transfer of charge during the interaction of COCl2 gas on SbNT material. Moreover, the phosgene molecules interaction on SbNT results in the variation of adsorption energy around -0.578 to -1.364 eV. Further, the average band gap changes are detected in the range of 1.75-19.3% for pristine SbNT, and 192.31-369.23% for Sn substituted SbNT material. The findings suggest that the physisorption of phosgene gas on Sn substituted SbNT is found to be more significant when compared to pristine SbNT. The current work shows that Sn substituted SbNT as a good base material to probe phosgene gas molecules.