Controlled Growth of Indium Selenides by High-Pressure and High-Temperature Method

The controlled growth of indium selenides has attracted considerable research interests in condensed matter physics and materials science yet remains a challenge due to the complexity of the indium–selenium phase diagram. Here, we demonstrate the successful growth of indium selenides in a controllable manner using the high-pressure and high-temperature growth technique. The γ-InSe and α-In2Se3 crystals with completely different stoichiometries and stacking manner of atomic layers have been controlled grown by subtle tuning growth temperature, duration time, and growth pressure. The as-grown γ-InSe crystal features a semiconducting property with a prominent photoluminescence peak of ∼1.23 eV, while the α-In2Se3 crystal is ferroelectric. Our findings could lead to a surge of interest in the development of the controlled growth of high-quality van der Waal crystals using the high-pressure and high-temperature growth technique and will open perspectives for further investigation of fascinating properties and potential practical application of van der Waal crystals.

Investigation of Bi2S3 nanorods photocatalytic activity under visible light for the degradation of dye from aquatic system

Bi2S3, 5 ml EG-Bi2S3, 10 ml EG-Bi2S3 was synthesized by employing solvothermal route. X-ray diffraction, UV-vis absorption, photoluminescence, Raman, scanning electron microscopic studies confirmed the structural, optical, morphological behaviors. The XRD pattern of Bi2S3, 5 ml EG-Bi2S3, 10 ml EG-Bi2S3 correlated well with JCPDS # 65-2435. The crystallite size was found to be 57, 49 and 40 nm. The photoluminescence spectra showed the semiconducting property of the prepared Bi2S3, 5 ml EG-Bi2S3, 10 ml EG-Bi2S3. The absorption spectra of the Bi2S3, 5 ml EG-Bi2S3, 10 ml EG-Bi2S3 nanorods were well matched with the spectra of the previous report. The band gap of the Bi2S3, 5 ml EG-Bi2S3, 10 ml EG-Bi2S3 was calculated to be 1.56, 1.45 and 1.3 eV in reducing order. The morphology of the Bi2S3, 5 ml EG-Bi2S3, 10 ml EG-Bi2S3 samples showed the development of nanorods. 10 ml EG-Bi2S3 sample showed better development of nanorods with the addition of ethylene glycol. The agglomeration was considerably reduced with the mixing of solvent. 10 ml EG- Bi2S3 sample investigated showed 86% of efficiency towards dye degradation. The narrow band gap, defined morphology of 10 ml EG- Bi2S3 made a positive result towards efficient photocatalytic activity.

Graphene-based Nano-Devices: Perfect Spin Seebeck and Pure Spin Photogalvanic Effects

We investigate the magnetic, thermoelectric transport, and photogalvanic effect (PGE) properties of two nano-devices based on sawtooth edged graphene nanoribbons (SGNRs). It is found that a robust spin-semiconducting property exists...

Fueling a Hot Debate on the Application of TiO2 Nanoparticles in Sunscreen

Titanium is one of the most abundant elements in the earth’s crust and while there are many examples of its bioactive properties and use by living organisms, there are few studies that have probed its biochemical reactivity in physiological environments. In the cosmetic industry, TiO2 nanoparticles are widely used. They are often incorporated in sunscreens as inorganic physical sun blockers, taking advantage of their semiconducting property, which facilitates absorbing ultraviolet (UV) radiation. Sunscreens are formulated to protect human skin from the redox activity of the TiO2 nanoparticles (NPs) and are mass-marketed as safe for people and the environment. By closely examining the biological use of TiO2 and the influence of biomolecules on its stability and solubility, we reassess the reactivity of the material in the presence and absence of UV energy. We also consider the alarming impact that TiO2 NP seepage into bodies of water can cause to the environment and aquatic life, and the effect that it can have on human skin and health, in general, especially if it penetrates into the human body and the bloodstream.

Comparison of X12Y12 (X=Al, B and Y=N, P) fullerene-like nanoclusters toward adsorption of dimethyl ether

Density functional theory (DFT) was used for studying the adsorption of dimethyl ether (DME) onto four nanoclusters: [Formula: see text] ([Formula: see text], B and [Formula: see text], P). The interaction energy along with the adsorption energy was investigated, and it was found that DME molecule has higher binding energies upon adsorption on Al-containing clusters, but on the other hand, it results in higher alteration in the electronic structure of B-containing cluster. Outcomes of charge analysis and frontier molecular orbital confirm higher alteration in the electronic structure of the later clusters, suggesting the possible potential of B[Formula: see text]N[Formula: see text] and B[Formula: see text]P[Formula: see text] as two sensitive sensors for DME. Nevertheless, Al-containing clusters showed much better adsorbent property, judging from their higher adsorption energies. The positive values of charge transfer upon DME adsorption confirm the p-type semiconducting property of all these clusters.

Infrared Spectra of Electronically Doped Polythiophene

Polythiophene was prepared by oxidation of thiophene. It was electronically doped with organic acceptors such as TCNE, TCNQ, DDQ, Chloranil and kI-I2. The FTIR spectra revealed only little change of intermolecular band gap of about 0.21ev of polythiophene .However, polythiophene (pure) obtained from chemical company revealed degenerate semiconducting property. The electronic doping with the organic acceptors and kI-I2 revealed optical properties in small polaron model in the FTIR range. Thus both non-degenerate and degenerate polythiophenes were studied with 60% doping of organic acceptors.