Adsorption of Phosgene Gas on Pristine and Copper-Decorated B12N12 Nanocages: A Comparative DFT Study

Ab Initio Study of the Graphyne-like γ-SiC Nanoflake for Toxic Gas-Sensing Applications

This study focuses on the geometrical, electronic, and optical properties of the γ-graphyne-like novel γ-SiC nanoflake of the γ-silicon carbide (SiC) monolayer using density functional theory calculations. γ-SiC was revealed to be a stable semiconducting nanoflake confirmed by a negative cohesive energy, real vibrational frequencies, and a 1.749 eV energy gap. The adsorption of COCl2, HCN, PH3, AsH3, CNCl, and C2N2 toxic gases on the γ-SiC nanoflake is also studied, which revealed an attractive gas-nanoflake interaction with the adsorption energy ranging from -0.21 to -0.38 eV. The adsorption results in a significant charge transfer between gas-adsorbent complexes. A significant variation in the energy gap and electrical conductivity was observed due to gas adsorption. γ-SiC showed maximum sensitivity at room temperature for CNCl gas. The entire process of adsorption is exothermic and thermodynamically stable. γ-SiC showed a high absorption coefficient over 104 orders with a significant variation in the absorption peak intensity and blue peak shifting. According to the quantum theory and reduced density gradient analysis, all of the gases are physisorbed on the γ-SiC nanoflake due to van der Waals interactions. The obtained results signify the usability of γ-SiC as a potential toxic gas sensor.

Anodic voltage performance of conducting polymer-functionalized boron nitride nanosheets: a DFT assessment

The search for low-diffusion barriers and high-capacity anode materials is considered a key step in boosting the efficiency of metal-ion batteries. Herein, we investigate the impact of a series of conducting polymers (CPs), namely, polyacetylene (PA), polypyrrole (PP), poly-p-phenylene (PPPh), and polythiophene (PT), on enhancing the material design and anodic performance of boron nitride nanosheet (BNNS)-based Li-ion and Na-ion batteries. For this purpose, first principle DFT simulations, utilizing both clustered and periodic models, are systematically performed to assess the stability of such nanostructures and their electronic behavior as potential anodic materials. It is revealed that frontier molecular orbitals calculated for BNNSs are stabilized upon association with the series of CPs, resulting in a reduction in the energy gaps of CP-BNNSs by nearly 50%, which in turn improves the charge transfer properties and cell reaction kinetics. A remarkable improvement in the cell voltage is predicted for PP and PT functionalized BNNSs, reaching approximately 3.5 V for Li+ and 3.0 V for Na+ ions. The outcome of the study emphasizes the influence of the size of metal ions, whether mono- or di-valent, and the nature of adsorbed conducting polymers. Manipulating the electronic features of boron nitride nanostructured surfaces through non-covalent functionalization with conducting polymers could pave the way for the design of highly efficient energy storage anodic CP-BNNS-based systems.

Assessing the efficacy of aluminum metal clusters Al13 and Al15 in mitigating NO2 and SO2 pollutants: a DFT investigation

The present investigation delves into the adverse environmental impact of atmospheric pollutant gases, specifically nitrogen dioxide (NO2) and sulfur dioxide (SO2), which necessitates the identification and implementation of effective control measures. The central objective of this study is to explore the eradication of these pollutants through the utilization of aluminum Al13 and Al15 metal clusters, distinguished by their unique properties. The comprehensive evaluation of gas/cluster interactions is undertaken employing density functional theory (DFT). Geometric optimization calculations for all structures are executed using the ωB97XD functional and the Def2-svp basis set. To probe various interaction modalities, gas molecule distribution around the metal clusters is sampled using the bee colony algorithm. Frequency calculations employing identical model chemistry validate the precision of the optimization calculations. The quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) methodologies are applied for the analysis of intermolecular interactions. This research establishes the robust formation of van der Waals attractions between the investigated gas molecules, affirming aluminum metal clusters as viable candidates for the removal and control of these gases.

Enhanced hydrogen storage of alkaline earth metal-decorated Bn (n = 3-14) nanoclusters: a DFT study

CONTEXT

Boron-based nanostructures hold significant promise for revolutionizing hydrogen storage technologies due to their exceptional properties and potential in efficiently accommodating and interacting with hydrogen molecules. In this paper, boron-based Bn (n = 3-14) nanoclusters decorated with alkaline earth metals (AEM = Ca and Be) were investigated for hydrogen storage applications based on density function theory (DFT) calculations. To evaluate H2 adsorption capability, the adsorption energies, frontier molecular orbitals (FMOs), natural bond orbital (NBO), and quantum theory of atoms in molecule (QTAIM) analysis are performed. The primary aim of this research work is to achieve targeted value of 5.5 wt% set by the US Department of Energy (DOE) for the year 2025. The results revealed that B5Ca2, B6Ca2, and B10Ca2 structures have the ability to hold up to 12H2 molecules with gravimetric capacities of 15.20, 14.21, and 8.60 wt%, respectively, when compared to other boron structures decorated with calcium. Similarly, for Be-decorated structure, B3Be2 structure can accommodate 3H2 molecules with gravimetric capacity of 10.59 wt%. The result of this study indicates that AEM-decorated Bn nanoclusters hold great promise as potential materials for hydrogen storage.

METHODS

Density functional theory (DFT) approach at ωB97XD/6-311++G(d,p) level of theory is employed to investigate the possibility of storing H2 molecules on alkaline earth metal (AEM = Ca and Be)-decorated Bn (n = 3-14) nanoclusters. All DFT computations were performed using Gaussian 09 software. To calculate frontier molecular orbitals (FMOs) and quantum theory of atoms in molecule (QTAIM) analysis, we have used GaussView and Multiwfn software, respectively.

Exploring the Sensing Potential of g-C3N4 versus Li/g-C3N4 Nanoflakes toward Hazardous Organic Volatiles: A DFT Simulation Study

Ab initio calculations were performed to determine the sensing behavior of g-C3N4 and Li metal-doped g-C3N4 (Li/g-C3N4) quantum dots toward toxic compounds acetamide (AA), benzamide (BA), and their thio-analogues, namely, thioacetamide (TAA) and thiobenzamide (TAA). For optimization and interaction energies, the ωB97XD/6-31G(d,p) level of theory was used. Interaction energies (Eint) illustrate the high thermodynamic stabilities of the designed complexes due to the presence of the noncovalent interactions. The presence of electrostatic forces in some complexes is also observed. The observed trend of Eint in g-C3N4 complexes was BA > TAA > AA > TBA, while in Li/g-C3N4, the trend was BA > AA > TBA > TAA. The electronic properties were studied by frontier molecular orbital (FMO) and natural bond orbital analyses. According to FMO, lithium metal doping greatly enhanced the conductivity of the complexes by generating new HOMOs near the Fermi level. A significant amount of charge transfer was also observed in complexes, reflecting the increase in charge conductivity. NCI and QTAIM analyses evidenced the presence of significant noncovalent dispersion and electrostatic forces in Li/g-C3N4 and respective complexes. Charge decomposition analysis gave an idea of the transfer of charge density between quantum dots and analytes. Finally, TD-DFT explained the optical behavior of the reported complexes. The findings of this study suggested that both bare g-C3N4 and Li/g-C3N4 can effectively be used as atmospheric sensors having excellent adsorbing properties toward toxic analytes.

Deciphering the electrochemical sensing capability of novel Ga12As12 nanocluster towards chemical warfare phosgene gas: insights from DFT

The applications of 3D inorganic nanomaterials in environmental and agriculture monitoring have been exploited continuously; however, the utilization of semiconductor nanoclusters, especially for detecting warfare agents, has not been fully investigated yet. To fill this gap, the molecular modelling of novel inorganic semiconductor nanocluster Ga12As12 as a sensor for phosgene gas (highly toxic for living things and the environment) is accomplished employing benchmark DFT and TD-DFT investigations. Computational tools have been applied to explore different adsorption sites and the potential sensing capability of the Ga12As12 nanoclusters. The calculated adsorption energy (-21.34 ± 2.7 kcal mol-1) for ten selected complexes, namely, Pgn-Cl@4m-ring (MS1), Pgn-Cl@6m-ring (MS2), Pgn-Cl@XY66 (MS3), Pgn-O@4m-ring (MS4), Pgn-O@XY66 (MS5), Pgn-O@XY64 (MS6), Pgn-O@Y (MS7), Pgn-planar@Y (MS8), Pgn-planar@X (MS9), and Pgn-planar@4m-ring (MS10), manifest the remarkable and excessive adsorption response of the studied nanoclusters. The explored molecular electronic properties, such as interaction distance (3.05 ± 0.5 Å), energy gap (∼2.17 eV), softness (∼0.46 eV), hardness (1.10 ± 0.01 eV), electrophilicity index (10.27 ± 0.45 eV), electrical conductivity (∼1.98 × 109), and recovery time (∼3 × 10-12 s-1) values, ascertain the elevated reactivity and an imperishable sensitivity of the Ga12As12 nanocluster, particularly for its complex MS8. QTAIM analysis exhibits the presence of a strong electrostatic bond (positive ∇2ρ(r) values), electron delocalization (ELF < 0.5), and a strong chemical bond (because of high all-electron density values). In addition, NBO analysis explores the lone pair electron delocalization of phosgene to the nanocluster stabilized by intermolecular charge transfer (ICT) and different kinds of non-covalent interactions. Also, the green region existence expressed by NCI analysis (between the nanocluster and adsorbate) stipulate the energetic and dominant interactions. Furthermore, the UV-Vis, thermodynamic analysis, and density of state (DOS) demonstrate the maximum absorbance (562.11 nm) and least excitation energy (2.21 eV) by the complex MS8, the spontaneity of the interaction process, and the significant changes in HOMO and LUMO energies, respectively. Thus, the Ga12As12 nanocluster has proven to be a promising influential sensing material to monitor phosgene gas in the real world, and this study will emphasize the informative knowledge for experimental researchers to use Ga12As12 as a sensor for the warfare agent (phosgene).

Designing of banana shaped chromophores via molecular engineering of terminal groups to probe photovoltaic behavior of organic solar cell materials

To meet the rising requirement of photovoltaic compounds for modernized hi-tech purpose, we designed six new molecules (DTPD1-DTPD6) from banana shaped small fullerene free chromophore (DTPR) by structural tailoring at terminal acceptors. Frontier molecular orbitals (FMOs), density of states (DOS), open circuit voltage (Voc), transition density matrix (TDM) analysis, optical properties, reorganization energy value of hole and electron were determined utilizing density function theory (DFT) and time-dependent density function theory (TD-DFT) approaches, to analyze photovoltaic properties of said compounds. Band gap contraction (∆E = 2.717-2.167 eV) accompanied by larger bathochromic shift (λmax = 585.490-709.693 nm) was observed in derivatives contrary to DTPR. The FMOs, DOS and TDMs investigations explored that central acceptor moiety played significant role for charge transformation. The minimum binding energy values for DTPD1-DTPD6 demonstrated the higher exciton dissociation rate with greater charge transferal rate than DTPR, which was further endorsed by TDM and DOS analyses. A comparable Voc (1.49-2.535 V) with respect to the HOMOPBDBT-LUMOacceptor for entitled compounds was investigated. In a nutshell, all the tailored chromophores can be considered as highly efficient compounds for promising OSCs with a good Voc response.

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.

A DFT and QTAIM insight into ethylene oxide adsorption on the surfaces of pure and metal-decorated inorganic fullerene-like nanoclusters

In this industrial era, the use of low-dimensional nanomaterials as gas sensors for environmental monitoring has received enormous interest. To develop an effective sensing method for ethylene oxide (EO), DFT computations are conducted using method ωB97X-D and B3LYP with 6-31G(d,p) basis set to evaluate the adsorption behavior of ethylene oxide gas on the surfaces of pristine, as well as Scandium and Titanium decorated B12N12, Al12N12, and Al12P12 nanocages. Several properties like structural, physical, and electronic are studied methodically to better understand the sensing behavior. Scandium-decorated aluminum phosphate and boron nitride nanocages were shown to perform better in terms of adsorption properties. The short recovery time observed in this study is beneficial for the repetitive use of the gas sensor. The Natural Bond Orbital and molecular electrostatic potential analysis demonstrated a substantial quantity of charge transfer from adsorbate to adsorbents. The bandgap alternation after adsorption shows an influence of adsorption on electronic properties. The interactions of adsorbate and adsorbents are further studied using the ultraviolet-visible predicted spectrum, and quantum theory of atoms in molecules all of which yielded promising findings.

Molecular engineering of Pyran‐fused acceptor–donor–acceptor‐type non‐fullerene acceptors for highly efficient organic solar cells—A density functional theory approach

The end‐capped modification proves that it is an excellent attempt to improve the solar cells performances. Therefore, nowadays, many researchers are working to design new molecules for potential use in organic photovoltaics. Herein, we have modified new molecules (SA1–SA5) from the reference (R) for fullerene‐free solar cells. These novel molecules have lower excitation energy levels that make the easier excitation in the excited state. Additionally, SA1 to SA5 molecules exhibit excellent charge mobility due to the modification of an efficient core units. Geometric and physiochemical investigations indicate that the modeled molecules are beneficial for efficient organic solar cells. The estimation of frontier molecular orbitals analysis, reorganizational energy, photovoltaic characteristics, and charge transmission calculations was done using density functional theory calculations with B3LYP/6‐31G (d, p) basis set. Among all designed molecules, SA3 has emerged as the preferred choice because of its outstanding photovoltaic characteristics, which include a minimal bandgap of 2.03 eV and reorganization energy of electron and holes of 0.0095 and 0.0077 eV, correspondingly. The designed materials (SA1–SA5) displayed a high λ max values, that is, 693.54 nm (in gas) and 679.63 nm (in chloroform). This theoretical framework suggests that the required photovoltaic properties may be efficiently obtained by remodeling the new molecules.

Transition Metal-Decorated Mg12O12 Nanoclusters as Biosensors and Efficient Drug Carriers for the Metformin Anticancer Drug

Drug carriers have been designed and investigated remarkably due to their effective use in the modern medication process. In this study, the decoration of the Mg₁₂O₁₂ nanocluster has been done with transition metals (Ni and Zn) for effective adsorption of metformin (anticancer drug). Decoration of Ni and Zn on a nanocluster allows two geometries, and similarly, the adsorption of metformin also provides two geometries. Density functional theory and time-dependent density functional theory have been employed at the B3LYP with 6-311G(d,p) level. The decoration of Ni and Zn offers good attachment and detachment of the drug, which is observed from their good adsorption energy values. Further, the reduction in the energy band gap is noted in the metformin-adsorbed nanocluster, which allows high charge transfer from a lower energy level to a high energy level. The drug carrier systems show an efficient working mechanism in a water solvent with the visible-light absorption range. Natural bonding orbital and dipole moment values suggested that the adsorption of the metformin causes charge separation in these systems. Moreover, low values of chemical softness with a high electrophilic index recommended that these systems are naturally stable with the least reactivity. Thus, we offer novel kinds of Ni- and Zn-decorated Mg₁₂O₁₂ nanoclusters as efficient carriers for metformin and also recommend them to experimentalists for the future development of drug carriers.

Enhancing the Photovoltaic Properties via Incorporation of Selenophene Units in Organic Chromophores with A2-π2-A1-π1-A2 Configuration: A DFT-Based Exploration

Currently, polymer organic solar cells (POSCs) are widely utilized due to their significant application, such as low-cost power conversion efficiencies (PCEs). Therefore, we designed a series of photovoltaic materials (D1, D2, D3, D5 and D7) by the incorporation of selenophene units (n = 1-7) as π₁-spacers by considering the importance of POSCs. Density functional theory (DFT) calculations were accomplished at MPW1PW91/6-311G (d, p) functional to explore the impact of additional selenophene units on the photovoltaic behavior of the above-mentioned compounds. A comparative analysis was conducted for designed compounds and reference compounds (D1). Reduction in energy gaps (∆E = 2.399 - 2.064 eV) with broader absorption wavelength (λ_max = 655.480 - 728.376 nm) in chloroform along with larger charge transference rate was studied with the addition of selenophene units as compared to D1. A significantly higher exciton dissociation rate was studied as lower values of binding energy (E_b = 0.508 - 0.362 eV) were noted in derivatives than in the reference (E_b = 0.526 eV). Moreover, transition density matrix (TDM) and density of state (DOS) data also supported the efficient charge transition origination from HOMOs to LUMOs. Open circuit voltage (V_oc) was also calculated for all the aforesaid compounds to check the efficiency, and significant results were seen (1.633-1.549 V). All the analyses supported our compounds as efficient POSCs materials with significant efficacy. These compounds might encourage the experimental researchers to synthesize them due to proficient photovoltaic materials.

Density Functional Theory Study of Cu-Modified B12N12 Nanocage as a Chemical Sensor for Carbon Monoxide Gas

The development of efficient B₁₂N₁₂-based toxic gas sensors has received considerable attention from the scientific community. Thus, in this regard, quantum chemical calculations were performed using density functional theory (DFT) at the B97D/6-31G(d,p) level for all of the studied systems. Modification of copper on B₁₂N₁₂ results in five optimized structures, named CuB₁₁N₁₂ and B₁₂N₁₁Cu (doped structures), Cu@b₆₆ and Cu@b₆₄ (decorated structures), and Cu@B₁₂N₁₂ (encapsulated structure). The results indicate that the CO gas weakly physisorbed on the B₁₂N₁₂ nanocage. It was found that the gas adsorption performance of B₁₂N₁₂ is improved due to the introduction of the Cu atom, but the interaction between CO and B₁₂N₁₁Cu, Cu@B₁₂N₁₂, Cu@b₆₄, and Cu@b₆₆ nanocages is strong, limiting the applications as a sensor. Particularly, the CuB₁₁N₁₂ system shows moderate adsorption (E_ads = -0.6 eV) and a high electronic sensitivity (ΔE_gap = 81.6%) toward CO gas, compared to other modified systems. Furthermore, based on the sensor performance analysis, it was found that CuB₁₁N₁₂ presented low recovery time (14 ms) and high selectivity for CO detection, making it a promising fast response sensor. Finally, our results demonstrated the capability of CuB₁₁N₁₂ as a superior sensor material for applications involving the selective detection of CO gas.

Unraveling the electronic influence and nature of covalent bonding of aryl and alkyl radicals on the B12N12 nanocage cluster

Carbon nanocage structures such as fullerene, nanotubes, nanocapsules, nanopolyhedra, cones, cubes, and onions have been reported since the discovery of C60, and they offer tremendous promise for investigating materials of low dimensions in an isolated environment. Boron Nitride (BN) nanomaterials such a: nanotubes, nanocapsules, nanoparticles, and clusters have been described in several studies and are predicted to be useful as electronic devices, high heat-resistance semiconductors, nanocables, insulator lubricants, and gas storage materials. The interaction, and electronic of octahedral B₁₂N₁₂ nanocage cluster covalently modified from the attachment of alkyl and aryl radicals were analyzed using Density Functional Theory calculations. The work discusses for the first time to our knowledge the complete investigation of the impact of the grafted aryl and alkyl groups on the electronic, bang gap, and density of states on the B₁₂N₁₂. Furthermore, this is the first complete description of these radicals attaching to a surface of B₁₂N₁₂ nanocage cluster.

Smart thermally responsive perovskite materials: Thermo-chromic application and density function theory calculation

With the continuous improvement of human's requirements for temperature control suitable for living, the energy consumption of electrical appliances such as air conditioners has become a major challenge in traditional architectural design. Generally, most of the solar energy passes through the glass to enter and exit the building, but the traditional glass can hardly control the light and heat energy, causing the indoor temperature to change dramatically with the environment. Therefore, it is more urgent to develop green and efficient smart windows. Perovskite is a temperature-adaptive material, which has the ability of phase transition and can adjust its band gap for thermochromic applications. In this work, we study the perovskite-based thermochromic smart window. As a new application of perovskite, a number of experiments have been carried out. However, there is still a lack of theoretical analysis on phase transition mechanisms and crystal structure prediction. Density functional theory (DFT) calculation is the most useful tool in optoelectronics, especially for perovskite crystal. Here, we extracted typical cases from published literature for analysis and comparison and summarized the crystal structure, electronic structure stability, interface engineering, and thermal characteristics employing DFT calculation We believe this work will pave the way for DFT application for the study of thermochromic perovskite.

Structural and electronic properties of H2, CO, CH4, NO, and NH3 adsorbed onto Al12Si12 nanocages using density functional theory

In this study, the adsorption of gases (CH₄, CO, H₂, NH₃, and NO) onto Al₁₂Si₁₂ nanocages was theoretically investigated using density functional theory. For each type of gas molecule, two different adsorption sites above the Al and Si atoms on the cluster surface were explored. We performed geometry optimization on both the pure nanocage and nanocages after gas adsorption and calculated their adsorption energies and electronic properties. The geometric structure of the complexes changed slightly following gas adsorption. We show that these adsorption processes were physical ones and observed that NO adsorbed onto Al₁₂Si₁₂ had the strongest adsorption stability. The E _g (energy band gap) value of the Al₁₂Si₁₂ nanocage was 1.38 eV, indicating that it possesses semiconductor properties. The E _g values of the complexes formed after gas adsorption were all lower than that of the pure nanocage, with the NH₃-Si complex showing the greatest decrease in E _g. Additionally, the highest occupied molecular orbital and the lowest unoccupied molecular orbital were analyzed according to Mulliken charge transfer theory. Interaction with various gases was found to remarkably decrease the E _g of the pure nanocage. The electronic properties of the nanocage were strongly affected by interaction with various gases. The E _g value of the complexes decreased due to the electron transfer between the gas molecule and the nanocage. The density of states of the gas adsorption complexes were also analyzed, and the results showed that the E _g of the complexes decreased due to changes in the 3p orbital of the Si atom. This study theoretically devised novel multifunctional nanostructures through the adsorption of various gases onto pure nanocages, and the findings indicate the promise of these structures for use in electronic devices.

Density functional theory study of Mobius boron-carbon-nitride as potential CH4, H2S, NH3, COCl2 and CH3OH gas sensor

The interesting properties of Mobius structure and boron-carbon-nitride (BCN) inspired this research to study different characteristics of Mobius BCN (MBCN) nanoribbon. The structural stability and vibrational, electrical and optical properties are analysed using the density functional theory. The gas-sensing ability of the modelled MBCN structure was also studied for methane, hydrogen sulfide, ammonia, phosgene and methanol gases. The negative adsorption energy and alteration of electronic bandgap verified that MBCN is very sensitive toward the selected gases. The complex structures showed a high absorption coefficient with strong chemical potential and 7 ps-0.3 ms recovery time. The negative change in entropy signifies that all the complex structures were thermodynamically stable. Among the selected gases, the MBCN showed the strongest interaction with methanol gas.

Exploration of the interesting photovoltaic behavior of the fused benzothiophene dioxide moiety as a core donor with modification in acceptors for high-efficacy organic solar cells

Non-fullerene-based chromophores with end-capped acceptor modification used in organic solar cells (OSCs) have proven to offer improved performance. Therefore, eight unique benzothiophene-based molecules (D2-D9) were designed by the end-capped acceptor manipulation of a reference molecule (R1). Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations at the B3LYP level were performed to investigate various parameters such as the optical properties, frontier molecular orbitals (FMOs), transition density matrix (TDM), binding energy, density of states (DOS), open-circuit voltage (V _oc), and reorganization energies of electrons (λ _e) and holes (λ _h), to better understand the optoelectronic properties of the newly designed compounds. All the derivatives had broader absorption spectra of 737.562-700.555 nm with a reduced energy gap of 2.132-1.851 eV compared to those of the reference (719.082 nm), except for D8 and D9. A comparable value of V _oc and lower reorganization energies were found in the derivatives compared to those of R1. Within the studied compounds, D3 was predicted to be a good optoelectronic material for environmentally friendly organic solar cells (EFOSCs) because of its superior optoelectronic capabilities, low-energy band gap (1.851 eV), highest λ _max values of 794.516 and 744.784 nm in chloroform and the gas phase, respectively, and lowest transition energy (1.561 eV) than those of the reference and the other derivatives. Subsequently, end-capped acceptor modification was proven to be an effective method to achieve desired optoelectronic characteristics.

Electrocatalytic activity of metal encapsulated, doped, and engineered fullerene-based nanostructured materials towards hydrogen evolution reaction

The utilization of nanostructured materials as efficient catalyst for several processes has increased tremendously, and carbon-based nanostructured materials encompassing fullerene and its derivatives have been observed to possess enhanced catalytic activity when engineered with doping or decorated with metals, thus making them one of the most promising nanocage catalyst for hydrogen evolution reaction (HER) during electro-catalysis. Prompted by these, and the reported electrochemical, electronic and stability advantage, an attempt is put forward herein to inspect the metal encapsulated, doped, and decorated dependent HER activity of C₂₄ engineered nanostructured materials as effective electro-catalyst for HER. Density functional theory (DFT) calculations have been utilized to evaluate the catalytic hydrogen evolution reaction activity of four proposed bare systems: fullerene (C₂₄), calcium encapsulated fullerene (Ca^encC₂₄), nickel-doped calcium encapsulated fullerene (Ni^dopCa^encC₂₄), and silver decorated nickel-doped calcium encapsulated (Ag^decNi^dopCa^encC₂₄) engineered nanostructured materials at the TPSSh/GenECP/6-311+G(d,p)/LanL2DZ level of theory. The obtained results divulged that, a potential decrease in energy gap (E_gap) occurred in the bare systems, while a sparing increase was observed upon adsorption of hydrogen onto the surfaces, these surfaces where also observed to maintain the least E_H–L gap while the Ag^decNi^dopCa^encC₂₄ surface exhibited an increased electrocatalytic activity when compared to others. The results also showed that the electronic properties of the systems evinced a correspondent result with their electrochemical properties, the Ag-decorated surface also exhibited a proficient adsorption energy \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$({E}_{ads}^{H})$$\end{document}(EadsH) and Gibb’s free energy (ΔG_H) value. The engineered Ag-decorated and Ni-doped systems were found to possess both good surface stability and excellent electro-catalytic property for HER activities.

Potential of B24O24 nanocluster for sensing and delivering chlormethine anticancer drug: a DFT study

In the present research, the adsorption and release of chlormethine (CM) drug on the B₂₄O₂₄ nanocage have been reported in the water media and gas phase at GGA/PBE/DNP computational level. The interaction between B₂₄O₂₄ nanocage and CM drug shows that adsorptions of the chlormethine on B₂₄O₂₄ nanocage for the most stable complexes are - 1.47 to - 1.36 eV in the gas phase and water media, respectively. The CM adsorption caused a notable change in the band gap (E_g) and work function (Φ) of the B₂₄O₂₄ nanocage in the studied complexes. The binding of chlormethine to B₂₄O₂₄ also significantly increased the polarity of the drug carrier, which is a desirable property for drug delivery in biological environments. CM drugs can be released from the nanocage in the presence of an external electric field along the X-axis direction. The present study results show that the B₂₄O₂₄ nanocage is a possible carrier for delivering chlormethine drugs.

Suitability of chlorobenzene-based single-electron transistor as HCN, AsH3, and COCl2 sensor

A density functional theory (DFT)-based first principle approach has been employed to investigate the suitability of chlorobenzene-based single-electron transistor (SET) for the detection of few toxic gases such as hydrogen cyanide, arsine, and phosgene. The adsorption aspect of toxic gas molecules on the chlorobenzene with different orientations has been analyzed. The attributes such as charge density, molecular energy spectrum, density of states, and Mulliken population have been computed to scrutinize the effect of gas molecules on the surface of chlorobenzene. The sensing mechanism of adsorbate (toxic gases) with the adsorbent (chlorobenzene) has been authenticated in a single-electron transistor (SET) environment through total energy vs. gate voltage plot and charge stability diagram. The recovery time of the chlorobenzene-based SET gas sensor on the adsorption of HCN, AsH₃, and COCl₂ has been computed as 1.93 ns, 0.45 ns, and 36.31 ns, respectively. Based on these findings, it is interesting to see that the COCl₂ gas molecule shows strong physical adsorption with the most significant adsorption distance (3.629 Å) with chlorobenzene, while AsH₃-adsorbed chlorobenzene SET displays a low recovery time in comparison with other considered gases. The present analysis confirms a significantly better range of detection and improved recovery time using chlorobenzene-based single-electron transistor.

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

Research into a gas sensing material with excellent performance to detect or remove toxic phosgene (COCl₂) is of great significance to environmental and biological protection. In the present work, the adsorption performance of COCl₂ 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 COCl₂ on pristine Pc and CuPc both belong to physisorption, indicating that they are not suitable gas sensing materials for COCl₂. When Pc sheets are decorated by Ga and Ru atoms, the adsorption of COCl₂ 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 COCl₂ 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 COCl₂ adsorption results in a significant conductivity variation of the RuPc monolayer, demonstrating it exhibits a high sensitivity to the COCl₂ molecule. Meanwhile, quick desorption processes were noticed at various temperatures for the COCl₂/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.

Nonfullerene Near-Infrared Sensitive Acceptors "Octacyclic Naphtho[1,2-b:5,6-b] Dithiophene Core" for Organic Solar Cell Applications: In Silico Molecular Engineering

End-capped modification is an efficient approach for enhancing the power conversion efficiency of organic solar cells (OSCs). Herein, five novel acceptor molecules have been designed by end-capper modification of the recently synthesized molecule NTIC (R). Different geometric and photovoltaic properties like frontier molecular orbital analysis, absorption maximum, transition density matrix analysis, reorganizational energy, binding energy, oscillator strength, energy of excitation, and charge transfer analysis of designed and reference molecules have been computed by employing density functional theory and time-dependent density functional theory. Designed molecules expressed a narrow energy band gap (E _g) with red-shifting in the absorption spectrum. Additionally, low excitation and binding energies are also noted in designed molecules. Excellent values of hole and electron reorganizational energies suggested that designed molecules are effective contributors to the development of the active layer of the organic solar cells. Further, a complex study is also performed for evaluation of charge transfer between the acceptor molecule and the donor polymer. Results of all analyses recommended that designed molecules are effective candidates for high-performance organic solar cell applications.

Efficient designing of half-moon-shaped chalcogen heterocycles as non-fullerene acceptors for organic solar cells

One key strategy to further improve the power conversion efficiency (PCE) of organic solar cells (OSCs) is to incorporate various complementary functional groups in a molecule. Such strategies proved attractive for tuning the photovoltaic performances of the materials and can show a much higher absorption phenomenon with narrower band gaps. Despite the outstanding benefits, materials selection and their efficient modeling is also an extremely challenging job for the development of OSCs materials. In this manuscript, we proficiently developed an efficient series of small molecule-based non-fullerene acceptors (SM-NFAs) SN1-SN9 for OSCs and characterized by density functional theory (DFT) and time-dependent DFT (TD-DFT). The characteristics required to estimate electron and hole mobility, and open-circuit voltage (V_oc) were investigated by optimizing the geometrical parameters, absorption spectra, exciton binding energy, frontier molecular orbitals (FMOs), electronic structures, and charge transfer rates. The outcomes of these materials showed that all newly constructed small-molecule-based non-fullerene acceptors exhibit broader and better absorption efficiency (λ_max = 761 to 778 nm) and exciton dissociation, while much lower LUMO energy levels which may help to enhance the reorganizational energies. Further, a narrow bandgap also offers better photovoltaic properties. Hence, the designed molecules exhibited narrow bandgap values (E_g = 2.82 to 2.98 eV) which are lower than that of the reference molecule (3.05 eV). High V_oc and photocurrent density values with lower excitation and binding energies eventually increase the PCEs of the OSC devices. The obtained results have shown that designed molecules could be effective aspirants for high-performance OSCs.

Exploration of the Intriguing Photovoltaic Behavior for Fused Indacenodithiophene-Based A-D-A Conjugated Systems: A DFT Model Study

Many researchers are engaged nowadays in developing efficient photovoltaic materials to accomplish the demand of modern technology. Nonfullerene small molecular acceptors (NF-SMAs) show potential photovoltaic performance, accelerating the development of organic solar cells (OSCs). Herein, the first theoretical designing of a series of indacenodithiophene-based (IDIC1-IDIC6) acceptor chromophores was done by structural tailoring with various well-known acceptors from the recently synthesized IDICR molecule. For the selection of the best level of density functional theory (DFT), various functionals such as B3LYP, M06-2X, CAM-B3LYP, and ωB97XD with the 6-311G(d,p) basis set were used for the UV-visible analysis of IDICR. Consequently, UV-visible results revealed that an interesting agreement was found between experimental and DFT-based values at the B3LYP level. Therefore, quantum chemical investigations were executed at the B3LYP/6-311G(d,p) level to evaluate the photovoltaic and optoelectronic properties. Structural tailoring with various acceptors resulted in a narrowing of the energy gap (2.245-2.070 eV) with broader absorption spectra (750.919-660.544 nm). An effective transfer of charge toward lowest unoccupied molecular orbitals (LUMOs) from highest occupied molecular orbitals (HOMOs) was studied, which played a crucial role in conducting materials. Further, open circuit voltage (V _oc) analysis was performed with respect to HOMO _PBDB-T -LUMO_ACCEPTOR, and all of the derivatives exhibited a comparable value of voltage with that of the parent chromophore. Lower reorganization energies in titled chromophores for holes and electrons were examined, which indicated the higher rate of mobility of charges. Interestingly, all of the designed chromophores exhibited a preferable optoelectronic response compared to the reference molecule. Therefore, this computed framework demonstrates that conceptualized chromophores are preferable and might be used to build high-performance organic solar cells in the future.

Density Functional Theory Study of Metallic Silicon (111) Plane Structures

The band structure on the surface might be influenced by the abruptly ended periodic structure and change the physical properties of the semiconductor. By using the density functional theory, this research also demonstrates that the Si unit cell has the calculated room-temperature electrical conductivity as 4.01 × 10^-6 (Ω^-1 cm^-1), similar to the experimental result. Thus, the Si(111) plane structures are calculated, and we found out that the one-layer and two-layer plane structures have the theoretical room-temperature electrical conductivities as 129.68 (Ω^-1 cm^-1) and 547.80 (Ω^-1 cm^-1), respectively. In addition, the results reveal that the conduction band and valance band of the Si(111) one-layer and two-layer structures will connect on the ⟨111⟩ direction, mainly contributed by Si 3p orbitals. Thus, the band structure at the ⟨111⟩ direction on the Si(111) surface has variation and increases the electrical conductivity to 7 to 8 orders compared to the intrinsic Si and offers new surface science and surface engineering concepts for future applications.

N/OB dative bond supplemented by N-HN/HC Hydrogen Bonds make BN-cages an attractive candidate for DNA-nucleobase adsorption – An MP2 prediction

The response of B12N12-nanocage towards DNA-nucleobases (adenine, guanine, cytosine, and thymine) is investigated using MP2 and DFT (M06-2X) levels of theory with 6-311+G** basis set. Multiple BN-cage-nucleobase structures for each...

Designing and Encapsulation of Inorganic Al12N12 Nanoclusters with Be, Mg, and Ca Metals for Efficient Hydrogen Adsorption: A Step Forward Towards Hydrogen Storage Materials

Nanoclusters such as [Formula: see text][Formula: see text] have received increased attention due to their diverse applications in the fields of optoelectronics and energy storage. In this paper, we have investigated a series of alkaline earth metal (AEM)-encapsulated [Formula: see text][Formula: see text] nanoclusters for hydrogen adsorption. Thermodynamic adsorption parameters, optical and nonlinear optical properties were investigated using density functional theory (DFT) at the B3LYP/6-31G(d,p) level of theory. Encapsulation of AEMs (Be, Mg and Ca) is an effective strategy to improve the NLO reaction and thermodynamic and adsorption properties of [Formula: see text][Formula: see text] nanoclusters. The adsorption energies ranging from [Formula: see text]26.57[Formula: see text]kJ/mol to [Formula: see text]213.33[Formula: see text]kJ/mol for the three guests (Be, Mg and Ca) capsulated [Formula: see text][Formula: see text] nanoclusters are observed. The adsorption energy is affected by the size of the nanocage. Therefore, Ca- and Mg-encapsulated cages show higher values of adsorption energy. Overall, an increase in adsorption energy ([Formula: see text][Formula: see text]kJ/mol to [Formula: see text]91.06[Formula: see text]kJ/mol) is observed for (Be, Mg and Ca) encapsulated [Formula: see text][Formula: see text] nanoclusters compared to untreated [Formula: see text][Formula: see text] and H2-[Formula: see text][Formula: see text] cages. Moreover, adsorption of hydrogen on AEMs encapsulated in [Formula: see text][Formula: see text] leads to a decrease in the HOMO-LUMO energy gap with an enhancement of linear and nonlinear hyperpolarizability. All hydrogen-adsorbed AEMs [Formula: see text][Formula: see text] nanocages exhibit large [Formula: see text] and [Formula: see text] values, suggesting that these systems are potential candidates for optical materials. Various geometrical parameters such as frontier molecular orbitals (FMOs), partial density of states, global quantum descriptor of reactivity, natural bond orbital testing and molecular electrostatic strength analyses were performed to investigate the thermodynamic stability of all the studied systems. The results obtained confirmed that the designed systems are suitable for hydrogen storage. Therefore, we recommend that these systems be investigated for their hydrogen storage and optical properties.

A Theoretical Framework of Zinc-Decorated Inorganic Mg12O12 Nanoclusters for Efficient COCl2 Adsorption: A Step Forward toward the Development of COCl2 Sensing Materials

Gas sensors are widely explored due to their remarkable detection efficiency for pollutants. Phosgene is a toxic gas and its high concentration in the environment causes some serious health problems like swollen throat, a change in voice, late response of nervous systems, and many more. Therefore, the development of sensors for quick monitoring of COCl2 in the environment is the need of the time. In this aspect, we have explored the adsorption behavior of late transition metal-decorated Mg12O12 nanoclusters for COCl2. Density functional theory at the B3LYP/6-31G(d,p) level is used for optimization, frontier molecular orbital analysis, dipole moment, natural bonding orbitals, bond lengths, adsorption energies, and global reactivity descriptor analysis. Decoration of Zn on pure Mg12O12 delivered two geometries named as Y1 and Y2 with adsorption energy values of -388.91 and -403.11 kJ/mol, respectively. Adsorption of COCl2 on pure Mg12O12 also delivered two geometries (X1 and X2) with different orientations of COCl2. The computed adsorption energy values of X1 and X2 are -44.92 and -71.32 kJ/mol. However, adsorption of COCl2 on Zn-decorated Mg12O12 offered two geometries named as Z1 and Z2 with adsorption energy values of -455.22 and -419.04 kJ/mol, respectively. These adsorption energy values suggested that Zn decoration significantly enhances the adsorption capability of COCl2 gas. Further, the narrow band gap and large dipole moment values of COCl2-adsorbed Zn-decorated Mg12O12 nanoclusters suggested that designed systems are efficient candidates for COCl2 adsorption. Global reactivity indices unveil the great natural stability and least reactivity of designed systems. Results of all analyses suggested that Zn-decorated Mg12O12 nanoclusters are efficient aspirants for the development of high-performance COCl2 sensing materials.

In Silico Designing of Nanoclusters with a Late Transition Metal for NO2 Adsorption: An Efficient Approach toward the Development of NO2 Sensing Materials

Gas sensors are widely used for detection of environmental pollution caused by various environmental factors such as road traffic and combustion of fossil fuels. Nitrogen dioxide (NO2) is one of the leading pollutants of the present age, which causes a number of serious health issues including acute bronchitis, cough, and phlegm, particularly in children. Nowadays, researchers are focused on designing new sensor materials for detection and removal of NO2 from the environment. In this line, we have made an attempt to design NO2 sensing materials by using theoretical techniques. Here, we have reported decoration of Mg12O12 nanoclusters with a late transition metal (Cu) by employing density functional theory at the B3LYP/6-31G(d,p) basis set. The decoration of metal on Mg12O12 gives two geometries (M1 and M2) with adsorption energies of -363.81 and -384.09 kJ/mol, respectively. Adsorption of NO2 on pristine Mg12O12 expressed an adsorption energy value of -62.36 kJ/mol. Adsorption of NO2 on Cu-decorated Mg12O12 nanocages delivered two geometries (N1 and N2) with adsorption energies of -442.56 and -447.64 kJ/mol. Metal-decorated Mg12O12 nanoclusters offer better adsorption of NO2 as compared to pristine Mg12O12 . Adsorption of NO2 on Cu-Mg12O12 nanoclusters also causes narrowing of band gap of magnesium oxide nanoclusters. Large dipole moment, high Q NBO with large electrophilic index in NO2-Cu-Mg12O12 nanoclusters suggested that metal-decorated Mg12O12 nanoclusters are efficient candidates for NO2 adsorption. Different geometric parameters and results of global reactivity descriptors show that NO2-Cu-Mg12O12 nanoclusters are quite stable in nature with least reactivity. Thus, conceptualized systems are potential candidates for applications in NO2 sensing materials.

Elucidating the Aromatic Properties of Covalent Organic Frameworks Surface for Enhanced Polar Solvent Adsorption

Covalent organic frameworks (COFs) have a distinguished surface as they are mostly made by boron, carbon, nitrogen and oxygen. Many applications of COFs rely on polarity, size, charge, stability and hydrophobicity/hydrophilicity of their surface. In this study, two frequently used COFs sheets, COF-1 and covalent triazine-based frameworks (CTF-1), are studied. In addition, a theoretical porous graphene (TPG) was included for comparison purposes. The three solid sheets were investigated for aromaticity and stability using quantum mechanics calculations and their ability for water and ethanol adsorption using molecular dynamics simulations. COF-1 demonstrated the poorest aromatic character due to the highest energy delocalization interaction between B–O bonding orbital of sigma type and unfilled valence-shell nonbonding of boron. CTF-1 was identified as the least kinetically stable and the most chemically reactive. Both COF-1 and CTF-1 showed good surface properties for selective adsorption of water via hydrogen bonding and electrostatic interactions. Among the three sheets, TPG’s surface was mostly affected by aromatic currents and localized π electrons on the phenyl rings which in turn made it the best platform for selective adsorption of ethanol via van der Waals interactions. These results can serve as guidelines for future studies on solvent adsorption for COFs materials.

Impact of Polypyrrole Functionalization on the Anodic Performance of Boron Nitride Nanosheets: Insights From First-Principles Calculations

Lithium-ion batteries (LIBs) have displayed superior performance compared to other types of rechargeable batteries. However, the depleting lithium mineral reserve might be the most discouraging setback for the LIBs technological advancements. Alternative materials are thus desirable to salvage these limitations. Herein, we have investigated using first-principles DFT simulations the role of polypyrrole, PP functionalization in improving the anodic performance of boron nitride nanosheet, BNNS-based lithium-ion batteries and extended the same to sodium, beryllium, and magnesium ion batteries. The HOMO-LUMO energy states were stabilized by the PP functional unit, resulting in a significantly reduced energy gap of the BNNS by 45%, improved electronic properties, and cell reaction kinetics. The cell voltage, ΔE_cell was predicted to improve upon functionalization with PP, especially for Li-ion (from 1.55 to 2.06 V) and Na-ion (from 1.03 to 1.37 V), the trend of which revealed the influence of the size and the charge on the metal ions in promoting the energy efficiency of the batteries. The present study provides an insight into the role of conducting polymers in improving the energy efficiency of metal-ion batteries and could pave the way for the effective design of highly efficient energy storage materials.