Enhanced electrical properties of amorphous In-Sn-Zn oxides through heterostructuring with Bi2Se3 topological insulators.

Amorphous indium tin zinc oxide (a-ITZO)/Bi2Se3 nanoplatelets (NPs) were fabricated using a two-step procedure. First, Bi2Se3 NPs were synthesized through thermal chemical vapor deposition at 600 °C on a glass substrate, and then a-ITZO was deposited on the surface of the Bi2Se3 NPs via magnetron sputtering at room-temperature. The crystal structures of the a-ITZO/Bi2Se3 NPs were determined via X-ray diffraction spectroscopy and high-resolution transmission electron microscopy. The elemental vibration modes and binding energies were measured using Raman spectroscopy and X-ray photoelectron spectroscopy. The morphologies were examined using field-emission scanning electron microscopy. The electrical properties of the a-ITZO/Bi2Se3 NPs were evaluated using Hall effect measurements. The bulk carrier concentration of a-ITZO was not affected by the heterostructure with Bi2Se3. In the case of the Bi2Se3 heterostructure, the carrier mobility and conductivity of a-ITZO were increased by 263.6% and 281.4%, respectively, whereas the resistivity of a-ITZO was reduced by 73.57%. This indicates that Bi2Se3 significantly improves the electrical properties of a-ITZO through its heterostructure, expanding its potential applications in electronic and thermoelectric devices.

Quantum computational investigation into structural, spectroscopic, topological and electronic properties of L-histidinium-L-tartrate hemihydrate: Nonlinear optical organic single crystal.

For the first time, a systematic investigation of optimization in the geometrical, vibrational, natural bonding orbital (NBO), electronic, linear and nonlinear optical properties, and Hirshfeld surface analysis for the L-histidinium-l-tartrate hemihydrate (HT) crystal is reported by employing the density functional theory (DFT). The geometrical parameters and vibrational frequencies obtained from the B3LYP/6-311++G(d,p) level of theory are in good agreement with the experimental values. The presence of strong hydrogen bonding interactions in the molecule causes an intense absorption peak in the infrared spectrum below 2000 cm-1. Quantum Theory of Atoms in Molecules (QTAIM) has been used to evaluate the topology of the electron density of a particular molecule to identify the critical points of the system using Multiwfn 3.8. These studies included ELF, LOL, and RDG studies. A time-dependent DFT approach is employed to obtain the excitation energies, oscillator strengths, and UV-Vis spectra for different solvents, such as methanol, ethanol, and water. The NBO analysis of the chosen compound, HT, is performed in terms of atom hybridization and electronic structure. The HOMO-LUMO energies and other associated electronic parameters are also computed. The nucleophilic sites are identified from MEP and Fukui functions analysis. The electrostatic potential and total density of states spectra of HT are discussed in detail. The theoretically obtained polarizability and first order hyperpolarizability values confirm that the grown material HT has NLO efficiency 15.771 times that of urea, and is proposed to be an exceptional nonlinear optical material. In addition, Hirshfeld surface analysis is performed to determine the inter-and intramolecular interactions in the title compound.

Zinc oxide nanostructures enhanced photoluminescence by carbon-black nanoparticles in Moiré heterostructures.

ZnO/carbon-black heterostructures were synthesized using a sol-gel method and crystallized by annealing at 500 °C under 2 × 10-2 Torr for 10 min. The crystal structures and binding vibration modes were determined by XRD, HRTEM, and Raman spectrometry. Their surface morphologies were observed by FESEM. The Moiré pattern that is observed in the HRTEM images confirms that the carbon-black nanoparticles were covered by the ZnO crystals. Measurements of optical absorptance revealed that the optical band gap of the ZnO/carbon-black heterostructures increased from 2.33 to 2.98 eV as the carbon-black nanoparticle content increases from 0 to 8.33 × 10-3 mol owing to the Burstein-Moss effect. The photoluminescence intensities at the near-band edge and of the violet, and blue light were increased by factors about 68.3, 62.8, and 56.8, respectively, when the carbon-black contents is of the 2.03 × 10-3 mol. This work reveals that the proper carbon-black nanoparticle content involved increases the PL intensities of the ZnO crystals in the short wavelength regime, supporting their potential application in the light-emitting devices.

DFT, hirshfeld and molecular docking studies of a hybrid compound - 2,4-Diamino-6-methyl-1,3,5-triazin-1-ium hydrogen oxalate as a promising anti -breast cancer agent.

The six-membered heterocyclic ring - 1,3,5-triazine and its derivatives have garnered a lot of attention because they're good bioactive herbicides, cancer agents, and other things. One such triazine derivative, 2,4-diamino-6-methyl-1,3,5-triazin-1-ium hydrogen oxalate (DMTHO), was produced in this work, and the structure was optimised using density functional theory's B3LYP functional and the basis set 6-31++G (d,p). Additionally, the chemical underwent in-depth research using molecular docking analysis, Hirshfeld, and density functional theory. The electron densities distribution in the atoms is provided by natural orbital analysis, which also characterises the chemical bonding and reaction behaviour of the compound. The calculated HOMO and LUMO energies indicate that charge transfer occurs inside the molecule. Chemical reactivity traits including HOMO-LUMO energy gaps, softness, total energy, chemical hardness, electronic chemical potential, and electrophilicity of bioactive substances have all been subjected to analytical investigation. Total dipole moment (µ) and first-order hyperpolarizability (ß) measurements for the investigated chemical indicate that DMTHO may exhibit microscopic nonlinear optical (NLO) behaviour with nonzero values. A quantitative description about intermolecular interactions in the produced crystal is provided by the Hirshfeld surface analysis. Further docking studies of the compound have been performed and the results reveals that the compound inhibit the breast cancer related protein - casein kinase (CK2) - and the possibility of developing as a potential anti breast cancer lead.

Fabrication of Three-Dimensional ZnO: Ga@ITO@Ag SERS-Active Substrate for Sensitive and Repeatable Detectability.

Vertically aligned ZnO: Ga nanotowers can be directly synthesized on a glass substrate with a ZnO seed film via the chemical bath method. A novel heterostructure of ZnO: Ga@ITO@Ag nanotowers was subsequently deposited in the ITO layer and Ag nanoparticles via the facile two-step ion-sputtering processes on the ZnO: Ga nanotowers. The appropriate ion-sputtering times of the ITO layer and Ag nanoparticles can benefit the fabrication of ZnO: Ga@ITO@Ag nanotowers with higher surface-enhanced Raman scattering (SERS) enhancement in detecting rhodamine 6G (R6G) molecules. Compared with ZnO: Ga@Ag nanotowers, ZnO: Ga@ITO@Ag nanotowers exhibited a high SERS enhancement factor of 2.25 × 108 and a lower detection limit (10-14 M) for detecting R6G molecules. In addition, the ITO layer used as an intermediate layer between ZnO: Ga nanotowers and Ag nanoparticles can improve SERS enhancement, sensitivity, uniformity, reusability, detection limit, and stability for detecting amoxicillin molecules. This phenomenon shall be ascribed to the ITO layer exhibiting a synergistic Raman enhancement effect through interfacial charge transfer for enhancing SERS activity. As a result, ZnO: Ga@ITO@Ag nanotowers can construct a three-dimensional SERS substrate for potential applications in environmentally friendly and cost-effective chemical or drug detection.

Effect of Composition Ratios on the Performance of Graphene/Carbon Nanotube/Manganese Oxide Composites toward Supercapacitor Applications.

Herein, we describe the preparation and characterization of graphene/carbon nanotube (CNT)/MnO v composites and the effects of chemical composition and phase transformation on the properties of the corresponding electrode film. In general, the effect of graphene-to-CNT ratio (G/C ratio) and the manganese (Mn) content on the morphology, chemical state, crystallization properties, and microstructure of the composite material was examined by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and selected area electron diffraction. The bonding mechanism between MnO v and graphite-based materials, that is, graphene and CNTs, is discussed. The influence of the composition of the composites on the performance of the electrode was investigated using charge-discharge curves. The faradically active MnO v also functioned as a considerable cobinder and allowed for a reduced amount of polymeric binder, which enhanced the conductivity and capacitance of the electrode. The optimized electrode composition was obtained based on our present graphene and CNT specifications. In summary, the results discussed in this article provide significant background information for future applications of graphene/CNT/MnO v composite electrodes.

Improving the Supercapacitor Performance by Dispersing SiO2 Microspheres in Electrodes.

This paper describes a simple, reproducible, and scalable procedure for the preparation of a SiO2-containing supercapacitor with high cycle stability. A carbon mesoporous material (CMM) with a high specific surface area, CMK-3, was adopted as an electric double-layer capacitor (EDLC) active material for the preparation of electrodes for the supercapacitor. The optimized SiO2 content decreased as the microsphere diameter decreased, and the optimal specific capacitance was obtained with 6 wt % SiO2 microspheres (100 nm size). The capacitance improved from 133 to 298 F/g. The corresponding capacitance retention rate after 1000 cycles increased from 68.04 to 91.53%. In addition, the energy density increased from 21.05 to 26.25 Wh/kg with a current density of 1 A/g. Finally, similar results based on active carbon, CeO2/CMK-3, and graphene/CNT/MnOv composite electrodes demonstrated that the proposed method exhibits wide compatibility with diverse electrode materials.

Controlled synthesis of highly dispersed platinum nanoparticles in ordered mesoporous carbons.

A novel route has been developed to fabricate ordered carbon mesoporous materials with well-dispersed, highly stable Pt nanoparticles of ca. 2-3 nm on the pore walls using platinum acetylacetonate as the co-feeding carbon and Pt precursor.

Synthesis of Strong Light Scattering Absorber of TiO2-CMK-3/Ag for Photocatalytic Water Splitting under Visible Light Irradiation.

The enhanced water splitting photocurrent has been observed through plasmonic mesoporous composite electrode TiO2-CMK-3/Ag under visible light irradiation. Strong light absorption achieved from the integrations of ordered mesoporous carbon (CMK-3) and silver plasmonic nanoparticles (NPs) layer in the TiO2, which significantly increased the effective optical depth of TiO2-CMK-3/Ag photoelectrode. The carbon-based CMK-3 also increased the surface wetting behavior and conductivity of the photoelectrodes, which resulted in a higher ion exchange rate and faster electron transport. The synthesis of high crystalline TiO2-CMK-3/Ag composite photocatalyst was verified by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Pronounced enhancement of light absorption of TiO2-CMK-3/Ag photoelectrode was confirmed by UV/vis spectrophotometers. Two orders of magnitude of the enhanced water splitting photocurrent were obtained in the TiO2-CMK-3/Ag composite photoelectrode with respect to TiO2 only. Finally, spatially resolved mapping photocurrents were also demonstrated in this study.

Honeycomb-like Porous Carbon-Cobalt Oxide Nanocomposite for High-Performance Enzymeless Glucose Sensor and Supercapacitor Applications.

Herein, we report the preparation of Pongam seed shells-derived activated carbon and cobalt oxide (∼2-10 nm) nanocomposite (PSAC/Co3O4) by using a general and facile synthesis strategy. The as-synthesized PSAC/Co3O4 samples were characterized by a variety of physicochemical techniques. The PSAC/Co3O4-modified electrode is employed in two different applications such as high performance nonenzymatic glucose sensor and supercapacitor. Remarkably, the fabricated glucose sensor is exhibited an ultrahigh sensitivity of 34.2 mA mM(-1) cm(-2) with a very low detection limit (21 nM) and long-term durability. The PSAC/Co3O4 modified stainless steel electrode possesses an appreciable specific capacitance and remarkable long-term cycling stability. The obtained results suggest the as-synthesized PSAC/Co3O4 is more suitable for the nonenzymatic glucose sensor and supercapacitor applications outperforming the related carbon based modified electrodes, rendering practical industrial applications.

Effect of Temperature Gradient Direction in the Catalyst Nanoparticle on CNTs Growth Mode.

To improve the understanding on CNT growth modes, the various processes, including thermal CVD, MP-CVD and ECR-CVD, have been used to deposit CNTs on nanoporous SBA-15 and Si wafer substrates with C(2)H(2) and H(2) as reaction gases. The experiments to vary process parameter of DeltaT, defined as the vector quantities of temperature at catalyst top minus it at catalyst bottom, were carried out to demonstrate its effect on the CNT growth mode. The TEM and TGA analyses were used to characterize their growth modes and carbon yields of the processes. The results show that DeltaT can be used to monitor the temperature gradient direction across the catalyst nanoparticle during the growth stage of CNTs. The results also indicate that the tip-growth CNTs, base-growth CNTs and onion-like carbon are generally fabricated under conditions of DeltaT > 0, <0 and ~0, respectively. Our proposed growth mechanisms can be successfully adopted to explain why the base- and tip-growth CNTs are common in thermal CVD and plasma-enhanced CVD processes, respectively. Furthermore, our experiments have also successfully demonstrated the possibility to vary DeltaT to obtain the desired growth mode of CNTs by thermal or plasma-enhanced CVD systems for different applications.

Adsorption of lysozyme on spherical mesoporous carbons (SMCs) replicated from colloidal silica arrays by chemical vapor deposition.

Spherical mesoporous carbons (SMC) were successfully synthesized by chemical vapor deposition (CVD) method using ferrocene as the carbon precursor and colloidal silica arrays as templates. The structure and textural properties of SMCs were characterized by a variety of techniques. Accordingly, a possible formation mechanism was proposed. These SMC materials were found to exhibit extraordinary high adsorption capacities (ca. 100mumol/g) for lysozyme (Lz) in solution with a pH value of 11 close to its isoelectric point. The correlations between the textural parameters of SMCs with Lz adsorption capacity were also investigated along with discussion on its adsorption kinetics and stability.