P=O Functionalized Black Phosphorus/1T-WS2 Nanocomposite High Efficiency Hybrid Photocatalyst for Air/Water Pollutant Degradation

Research on layered two-dimensional (2D) materials is at the forefront of material science. Because 2D materialshave variousplate shapes, there is a great deal of research on the layer-by-layer-type junction structure. In this study, we designed a composite catalyst with a dimension lower than two dimensions and with catalysts that canbe combined so that the band structures can be designed to suit various applications and cover for each other’s disadvantages. Among transition metal dichalcogenides, 1T-WS2 can be a promising catalytic material because of its unique electrical properties. Black phosphorus with properly controlled surface oxidation can act as a redox functional group. We synthesized black phosphorus that was properly surface oxidized by oxygen plasma treatment and made a catalyst for water quality improvement through composite with 1T-WS2. This photocatalytic activity was highly efficient such that the reaction rate constant k was 10.31×10−2 min−1. In addition, a high-concentration methylene blue solution (20 ppm) was rapidly decomposed after more than 10 cycles and showed photo stability. Designing and fabricating bandgap energy-matching nanocomposite photocatalysts could provide a fundamental direction in solving the future’s clean energy problem.

Crystallographic and optical properties of wide bandgap photovoltaic semiconductor system, Cu(Al,In)Se2

We characterized the optical and electronic properties of chalcopyrite-type Cu(Al,In)Se2, which is a candidate for wide-bandgap solar cell materials. The bandgap energy was determined from diffuse reflectance spectra. The band gap energy increased from 1.00 eV for CuInSe2 to 2.61 eV for CuAlSe2 with an increase in the Al content. The ionization energy corresponding to the energy levels of the valence band maximum (VBM) was determined using photoemission yield spectroscopy (PYS). The VBM level of the Cu(Al,In)Se2 system stayed relatively constant, but the conduction band minimum (CBM) level increased with increasing Al content. To analyze the local structures of Cu and In atoms in Cu(Al,In)Se2, Cu and In K-edge X-ray absorption fine structure (XAFS) spectra were measured at SPring-8. We discuss the crystallographic characteristics of Cu(Al,In)Se2 based on the results of the XAFS analyses and a comparison of the phase diagrams of the Cu2Se-Al2Se3, Cu2Se-In2Se3, and Cu2Se-Ga2Se3 systems.

Optical Characterization of Quinoline Yellow Fluorochemosensors for Analyzing Its Photonics Applications With Synthesized Nano Particles

Quinoline Yellow (QY) with the scientific name [sodium 2-(2, 3-dihydro-1,3-dioxo-1H-inden-2-yl) quinoline-6,8-disulfonate] (SQDS) is investigated for its sensing properties as fluorochemosensors and its NLO applications. Pure SQDS is doped with copper ferrite and cerium oxide nanoparticles and studied for changes in spectral results. Change in absorption spectrum is observed depending on the polarity of solvents. Intensity of fluorescence also varies with different type of solvents. Optical characterization for SQDS is carried out via various spectroscopic techniques including UV-VIS spectroscopy, FTIR spectroscopy, Scanning Electron Microscopy and Photo Luminescence (PL) spectroscopy. Optical parameters like extinction coefficient, refractive index and bandgap energy are determined from absorption spectrum for both solution and film samples. XRD characterization is also performed for QY and for nanoparticle doped QY. For investigating Non-Linear optical (NLO) application of QY, films are prepared and optical imaging is performed via Atomic Force Microscopy (AFM). Characterization results are analysed and predicted for application in non-linear optics.

Robust Molecular Dipole Induced Surface Functionalization of Inorganic Perovskites for Efficient Solar Cells

CsPbI3 inorganic perovskite shows high potential for single-junction or tandem solar cells due to its suitable bandgap energy (Eg=~1.7 eV), but defect-assisted nonradiative recombination and unmatched interfacial band alignment within...

Reversible Room Temperature H2 Gas Sensing Based on Self-Assembled Cobalt Oxysulfide

Reversible H2 gas sensing at room temperature has been highly desirable given the booming of the Internet of Things (IoT), zero-emission vehicles, and fuel cell technologies. Conventional metal oxide-based semiconducting gas sensors have been considered as suitable candidates given their low-cost, high sensitivity, and long stability. However, the dominant sensing mechanism is based on the chemisorption of gas molecules which requires elevated temperatures to activate the catalytic reaction of target gas molecules with chemisorbed O, leaving the drawbacks of high-power consumption and poor selectivity. In this work, we introduce an alternative candidate of cobalt oxysulfide derived from the calcination of self-assembled cobalt sulfide micro-cages. It is found that the majority of S atoms are replaced by O in cobalt oxysulfide, transforming the crystal structure to tetragonal coordination and slightly expanding the optical bandgap energy. The H2 gas sensing performances of cobalt oxysulfide are fully reversible at room temperature, demonstrating peculiar p-type gas responses with a magnitude of 15% for 1% H2 and a high degree of selectivity over CH4, NO2, and CO2. Such excellent performances are possibly ascribed to the physisorption dominating the gas–matter interaction. This work demonstrates the great potentials of transition metal oxysulfide compounds for room-temperature fully reversible gas sensing.

Synthesis and Characterization of SnO2 Thin Film Semiconductor for Electronic Device Applications

Synthesis and characterization of SnO2 thin films with various types of doping materials such as aluminum, fluorine and indium have been successfully carried out. This study aims to determine the effect of various types of doping materials on the quality of thin films such as the energy band gap produced. The results showed that the higher the doping concentration, the more transparent the layer formed. In addition, the optical properties of thin films such as band gap energy are affected by the applied doping. The direct and indirect values ​​of the largest band gap energy for the percentage of 95:5% are 3.62 eV and 3.92 eV are found in the SnO2: In thin layer. Meanwhile, the lowest direct and indirect values ​​of band gap energy are in the thin layer of SnO2:(Al+F+In) for a percentage of 85:15%, namely 3.41 eV and 3.55 eV. The greater the amount of doping given, the smaller the bandgap energy produced. In addition, the more combinations of doping mixtures (aluminum, fluorine, and indium) given, the smaller the bandgap energy produced. This shows that the quality of a thin film of SnO2 produced is influenced by the amount of concentration and the type of doping used

Synthesis of azo polymers by etheric derivatives polymerization of allyl bromide and studying their bandgap and determine some of their properties: اصطناع بوليميرات آزو ببلمرة مشتاقات إيتيرية لبروميد الآليل ودراسة فجوتها الطاقية وتعيين بعض خصائصها الفيزيائية

In this research, two ether derivatives of phenolic azo dyes were synthesized via Williamson's reaction according to the SN2 mechanism. The prepared compounds were radically polymerized using (AIBN) as an initiator and their structures were identified by FT-IR and 1H-NMR. Furthermore, thermal properties of these polymers was made by (DSC). Bandgap energy have been calculated to indicate the ability of these polymers as optical semiconductors, it was 2.8ev, 2.4ev for P(AO2) and P(AON1) respectively. Beside the determination of refractive index, kinematic viscosity, density, and degree of Turbidity.

Synthesis of Atmospherically Stable Zero-Valent Iron Nanoparticles (nZVI) for the Efficient Catalytic Treatment of High-Strength Domestic Wastewater

Here, we report the fabrication of nZVI by the wet chemical technique in the presence of ethanol using ferric iron and sodium borohydride as the reducing agents under ambient conditions. The obtained nZVI particles are mainly in a zero-valent oxidation state and do not undergo significant oxidation for several weeks. The structural and morphological parameters of nZVI were investigated by using UV, XRD, SEM, EDX, TEM, and DLS analysis. The optical nature, bandgap energy, and absorption edge were all revealed by the UV–visible spectrum. The phase development and crystallinity of nZVI particles were shown by the XRD pattern. The morphological investigation revealed that the nanoparticles were spherical with an average size of 34–110 nm by using ImageJ software, and the elemental analysis was analyzed using EDX. Furthermore, the catalytic treatment performance of domestic wastewater was evaluated in terms of pH, COD (chemical oxygen demand) solubilization, total solids (TS), volatile solids (VS), phosphorous, and total nitrogen (TN) reduction under aerobic and anaerobic operating conditions. The effluent was subjected to a process evaluation with a different range (100–500 mg/L) of nZVI dosages. The COD solubilization and suspended solids reduction were significantly improved in the anaerobic condition in comparison to the aerobic condition. Furthermore, the effect of nZVI on phosphorous (PO43−) reduction was enhanced by the electrons of iron ions. The high concentration of nZVI dosing has a positive impact on COD solubilization and phosphorous removal regardless of the aeration condition with 400 mg/L of nZVI dosage.