Exploring the anodic performance of ScSeS and TiSeS monolayers of modified transition metal dichalcogenides for Mg ion batteries via DFT calculations.

Due to the significant ambient abundance of magnesium metal and the divalent nature of the magnesium ion, rechargeable magnesium-ion batteries are a strong candidate to fulfill the forthcoming demands for electrical energy storage in both extensive mobile and stationary applications. Transition metal dichalcogenides (TMDs) are still regarded as newcomers within the realm of 2D nanomaterials, particularly in the context of their applications in energy storage. Here, we report a DFT-based analysis on TMDs as anode materials in Mg ion batteries using the GGA-PBE exchange-correlation functional. This study investigates the structural, electronic and adsorption behavior of ScSeS and TiSeS nanosheets. All predicted TMDs adsorbed Mg-atoms with favorable adsorption energy (Eads) without any noticeable structural distortion, exhibiting good structural stability. For three distinct adsorption sites, top of the transition metal (Sc, Ti), Se and S, the Eads are calculated as -3.74 eV, -3.62 eV, -3.40 eV and -1.23 eV, -1.38 eV, -0.91 eV, which indicates that Eads is higher when the Mg ion is adsorbed at the Sc and Se atomic sites, respectively. The Eads for ScSeS are almost two times the Eads for TiSeS. In the band structure, it is seen that for both ScSeS and TiSeS, the conduction band crosses the Fermi level, which implies the metallic behavior of the nanosheets. Furthermore, they show a maximum theoretical specific capacity of about 686.18 mA h g-1 and 546.63 mA h g-1, which is almost two times higher than that of the bulk graphite anode material. The average open circuit voltages are calculated as 0.43 V and 0.11 V for ScSeS and TiSeS, respectively.

Tuning the electrochemical behavior of graphene oxide and reduced graphene oxide via doping hexagonal BN for high capacity negative electrodes for Li and Na ion batteries.

Inspired by the recently synthesized hexagonal boron nitride (h-BN) doped graphene, density functional theory (DFT) calculations were performed to evaluate the anodic properties of BN doped graphene (BN-G), graphene oxide (BN-GO) and reduced graphene oxide (BN-rGO) for Li/Na ion batteries (LIBs/NIBs). Our proposed materials show a semiconducting character with band gaps of 1.4, 0.67 and 0.45 eV for BN-G, BN-GO and BN-rGO, respectively. Among the three nanosheets, BN-rGO shows strong interaction behavior with Li/Na whereby the defected site exhibits high reactivity compared to the other adsorption sites. The adsorption energies are found to be about -4.72/-4.10 eV for Li/Na at the defected site, which are consecutively 3 and 2 times stronger than the adsorption energies of BN-G and BN-GO. It is predicted by partial density of states (PDOS) and band structure analysis that the nanosheets will exhibit metallic behavior through the adsorption process. Relatively low diffusion barriers are found to be about 0.47 and 0.22 eV when Li and Na moved from one adsorption site to another nearby adsorption site on BN-rGO. Among them, BN-rGO shows a high specific capacity, about 1583 and 1319 mA h g-1 for LIBs and NIBs. Therefore, the suitable adsorption energy with metallic behavior of the nanosheet combined with the high specific capacity confirm that BN-rGO is a promising anode candidate for Li/Na ion batteries.

Exploring the adsorption ability with sensitivity and reactivity of C12-B6N6, C12-Al6N6, and B6N6-Al6N6 heteronanocages towards the cisplatin drug: a DFT, AIM, and COSMO analysis.

The DFT study on the adsorption behaviour of the C24, B12N12, and Al12N12 nanocages and their heteronanocages towards the anticancer drug cisplatin (CP) was performed in gas and water media. Among the three pristine nanocages, Al12N12 exhibited high adsorption energy ranging from -1.98 to -1.63 eV in the gas phase and -1.47 to -1.39 eV in water media. However, their heterostructures C12-Al6N6 and B6N6-Al6N6 showed higher interaction energies (-2.22 eV and -2.14 eV for C12-Al6N6 and B6N6-Al6N6) with a significant amount of charge transfer. Noteworthy variations in electronic properties were confirmed by FMO analysis and DOS spectra analysis after the adsorption of the cisplatin drug on B12N12 and B6N6-Al6N6 nanocages. Furthermore, an analysis of quantum molecular descriptors unveiled salient decrement in global hardness and increments in electrophilicity index and global softness occurred after the adsorption of CP on B12N12 and B6N6-Al6N6. On the other hand, the above-mentioned fluctuations are not so noteworthy in the case of the adsorption of CP on Al12N12, C12-B6N6, and C12-Al6N6. Concededly, energy calculation, FMO analysis, ESP map, DOS spectra, quantum molecular descriptors, dipole moment, COSMO surface analysis, QTAIM analysis, and work function analysis predict that B12N12 and B6N6-Al6N6 nanocages exhibit high sensitivity towards CP drug molecules.

Trivalent and pentavalent atoms doped boron nitride nanosheets as Favipiravir drug carriers for the treatment of COVID-19 using computational approaches.

In our DFT investigations, pristine BNNS as well as trivalent and pentavalent atoms doped BNNS have been taken into consideration for Favipiravir (FPV) drug carriers for the treatment of COVID-19. Among the nanosheets, In doped BNNS (BN(In)NS) interacts with FPV by favorable adsorption energies about -2.44 and -2.38 eV in gas and water media respectively. The charge transfer analysis also predicted that a significant amount of charge about 0.202e and 0.27e are transferred to BN(In)NS in gas and water media respectively. HOMO and LUMO energies are greatly affected by the adsorption of FPV on BN(In)NS and energy gap drastically reduced by about 38.80 % and 64.07 % in gas and water media respectively. Similar results are found from the global indices and work function analysis. Therefore, it is clearly seen that dopant In atom greatly modified the BNNS and enhanced the adsorption behavior along with sensitivity, reactivity, polarity towards the FPV.

In-plane graphene/boron nitride heterostructures and their potential application as toxic gas sensors.

After the successful synthesis of graphene/hexagonal boron nitride (h-BN) heterostructures, research works have been carried out for their plausible real-world device applications. Such 2D nanosheets gain great attention as they have shown promising gas sensing properties due to their high surface-to-volume ratio and unique electronic properties between graphene and h-BN. Herein, we report a first-principles density functional theory investigation of the structural and electronic properties of pristine graphene (PG), pristine BN, and their in-plane heterostructures employing B3LYP and dispersion-corrected van der Waals functional WB97XD with the 6-311G (d, p) basis set. We found that these predicted nanosheets show good structural stability with favorable cohesive energy and the bandgap gradually increases with the increase in the B-N concentration. We have also studied their adsorption properties toward toxic gas molecules (SO2 and CO). Among these heterostructures, G2BN2 exhibits greater adsorption energy of about -0.237 eV and -0.335 eV when exposed to SO2 and CO gas molecules, respectively. The electronic properties such as HOMO and LUMO energies, HOMO-LUMO energy gap, Fermi level, work function, and conductivity significantly changed after the adsorption of SO2 gas on the nanosheets except for PG, whereas these parameters remain almost the same after the adsorption of the CO gas molecule. Mulliken and natural bond orbital (NBO) charge analysis reveals that charge transfer occurs from gas molecules to the nanosheets except when SO2 is adsorbed onto PG. Although the adsorption energies for CO gas are slightly greater than those for SO2 gas for these nanosheets, all other investigations such as electronic properties, charge transfer analysis, molecular electrostatic potential (MEP) map, and global indices predict that these nanosheets are good sensors for SO2 gas than CO gas molecules.

Surface adsorption of nitrosourea on pristine and doped (Al, Ga and In) boron nitride nanosheets as anticancer drug carriers: the DFT and COSMO insights.

To minimize the side effects of chemotherapeutic drugs and enhance the effectiveness of cancer treatment, it is necessary to find a suitable drug delivery carrier for anticancer drugs. Recently nanomaterials are extensively being studied as drug vehicles and transport drugs in tumor cells. Using DFT calculations, the adsorption behavior with electronic sensitivity and reactivity of pristine and doped (Al, Ga and In)-BNNS towards the nitrosourea (NU) drug has been investigated in gas as well as water media. Our calculations showed that the NU drug is physically adsorbed on the pristine BNNS with -0.49 and -0.26 eV by transferring little amount of charge of about 0.033e and 0.046e in gas and water media in the most stable complex. But after replacing one of the central B atoms with an Al or Ga or In atom, the sensitivity of the doped BNNS remarkably enhances towards the NU drug molecules. The NU drug prefers to be chemically adsorbed on the BN(Al)NS, BN(Ga)NS and BN(In)NS by -1.28, -1.58 and -3.06 eV in the gas phase and -1.34, -1.23 and -3.65 eV in water media in the most stable complexes respectively. The large destabilization of LUMO energies after the adsorption of the NU drug on the BN(Al)NS, BN(Ga)NS and BN(In)NS significantly reduces their E g from 4.37 to 0.69, 4.37 to 1.04 and 4.33 to 0.66 eV in the S1 complex respectively. The reduction of E g of doped BNNS by the NU drug greatly enhances the electrical conductivity which can be converted to an electrical signal. Therefore, this doped BNNS can be used as a fascinating electronic sensor for the detection of NU drug molecules. Furthermore the work function of the doped BNNS was largely affected by the NU drug adsorption about 47.3%, 39.3% and 40.4% in the gas phase and 41.3%, 36.6% and 31.6% in water media in the S1 complex of NU/BN(Al)NS, NU/BN(Ga)NS and NU/BN(In)NS respectively. Thus, the doped BNNS may be used as a Ф type sensor for NU drug molecules.

A DFT study on the geometrical structures, electronic, and spectroscopic properties of inverse sandwich monocyclic boron nanoclusters ConBm (n = 1.2; m = 6-8).

Recent photoelectron spectroscopy and computational studies have shown that boron ring-centered transition metal-doped inverse sandwich complexes prefer planar or quasi-planar structures which could be a potential building blocks for designing better nanosystems with tailored properties. Due to promising technological applications of different boron nanoclusters, we present a study on the structural, electronic, magnetic, and spectroscopic properties of Co-centered inverted sandwich monocyclic boron nanoclusters with pyramidal, CoBn, and bi-pyramidal, Co2Bn (n = 6-8) shapes. The investigations have been carried out on previously reported stable hexa-, hepta-, and octagonal hole containing pyramidal and bi-pyramidal boron clusters by employing density functional theory calculations with B3LYP hybrid exchange-correlation functional. Our calculation suggests that all the global minima structures have stable planar or quasiplanar symmetrical cyclic motif. The structural stability of clusters has been investigated by analyzing binding energy, thermodynamical parameters, vibrational spectra etc. All parameters indicate that the bi-pyramidal structures (Co2B6, Co2B7, and Co2B8) are more stable than both pristine and singly doped boron nanoclusters. On the contrary, the bi-pyramidal cluster is chemically less stable than the pyramidal clusters (except CoB7) which is supported by the ionization potential, electron affinity, energy gap, and global indices calculations. Molecular electrostatic potential surface and HOMO-LUMO analysis have been carried out to understand the thermodynamically stable clusters that arises due to specific inter/intra-molecular interactions. The presence of magnetic element (Co) in the clusters induces ferromagnetic properties which have been found by investigating the magnetic moment, spin density, and DOS spectra analysis. Size and geometry-dependent properties of boron nanoclusters have been observed as evident from the energy gap and optical absorptions analysis.