scholarly journals Sustainable Hydrogen Production from Starch Aqueous Suspensions over a Cd0.7Zn0.3S-Based Photocatalyst

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 870
Author(s):  
Anna Y. Kurenkova ◽  
Tatiana B. Medvedeva ◽  
Nikolay V. Gromov ◽  
Andrey V. Bukhtiyarov ◽  
Evgeny Y. Gerasimov ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Corn Starch ◽  
Diffuse Reflectance Spectroscopy ◽  
Photocatalytic Reaction ◽  
X Ray ◽  
Before And After ◽  
Hydrolysis Temperature ◽  
Pretreatment Conditions

We explored the photoreforming of rice and corn starch with simultaneous hydrogen production over a Cd0.7Zn0.3S-based photocatalyst under visible light irradiation. The photocatalyst was characterized by UV–vis diffuse reflectance spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The influence of starch pretreatment conditions, such as hydrolysis temperature and alkaline concentration, on the reaction rate was studied. The maximum rate of H2 evolution was 730 μmol·h−1·g−1, with AQE = 1.8% at 450 nm, in the solution obtained after starch hydrolysis in 5 M NaOH at 70 °C. The composition of the aqueous phase of the suspension before and after the photocatalytic reaction was studied via high-performance liquid chromatography, and such products as glucose and sodium gluconate, acetate, formate, glycolate, and lactate were found after the photocatalytic reaction.

scholarly journals Incorporating N Atoms into SnO2 Nanostructure as an Approach to Enhance Gas Sensing Property for Acetone

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 445 ◽  
Author(s):  
Xiangfeng Guan ◽  
Yongjing Wang ◽  
Peihui Luo ◽  
Yunlong Yu ◽  
Dagui Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gas Sensor ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Gas Sensing ◽  
Diffuse Reflectance Spectroscopy ◽  
Limit Of Detection ◽  
Low Cost ◽  
X Ray ◽  
Sno2 Nanostructure

The development of high-performance acetone gas sensor is of great significance for environmental protection and personal safety. SnO2 has been intensively applied in chemical sensing areas, because of its low cost, high mobility of electrons, and good chemical stability. Herein, we incorporated nitrogen atoms into the SnO2 nanostructure by simple solvothermal and subsequent calcination to improve gas sensing property for acetone. The crystallization, morphology, element composition, and microstructure of as-prepared products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Electron paramagnetic resonance (EPR), Raman spectroscopy, UV–visible diffuse reflectance spectroscopy (UV–vis DRS), and the Brunauer–Emmett–Teller (BET) method. It has been found that N-incorporating resulted in decreased crystallite size, reduced band-gap width, increased surface oxygen vacancies, enlarged surface area, and narrowed pore size distribution. When evaluated as gas sensor, nitrogen-incorporated SnO2 nanostructure exhibited excellent sensitivity for acetone gas at the optimal operating temperature of 300 °C with high sensor response (Rair/Rgas − 1 = 357) and low limit of detection (7 ppb). The nitrogen-incorporated SnO2 gas sensor shows a good selectivity to acetone in the interfering gases of benzene, toluene, ethylbenzene, hydrogen, and methane. Furthermore, the possible gas-sensing mechanism of N-incorporated SnO2 toward acetone has been carefully discussed.

scholarly journals Novel Carbon Dots Derived from Glycyrrhizae Radix et Rhizoma and Their Anti-Gastric Ulcer Effect

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1512
Author(s):  
Yuhan Liu ◽  
Meiling Zhang ◽  
Jinjun Cheng ◽  
Yue Zhang ◽  
Hui Kong ◽  
...  
Keyword(s):  
Gastric Ulcer ◽  
Photoelectron Spectroscopy ◽  
Carbon Dots ◽  
High Performance ◽  
Raw264.7 Cells ◽  
Mice Model ◽  
X Ray ◽  
Glycyrrhizae Radix ◽  
Transmission Electron ◽  
High Resolution Tem

Glycyrrhizae Radix et Rhizoma (GRR) is one of the commonly used traditional Chinese medicines in clinical practice, which has been applied to treat digestive system diseases for hundreds of years. GRR is preferred for anti-gastric ulcer, however, the main active compounds are still unknown. In this study, GRR was used as precursor to synthesize carbon dots (CDs) by a environment-friendly one-step pyrolysis process. GRR-CDs were characterized by using transmission electron microscopy, high-resolution TEM, fourier transform infrared, ultraviolet-visible and fluorescence spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and high-performance liquid chromatography. In addition, cellular toxicity of GRR-CDs was studied by using CCK-8 in RAW264.7 cells, and the anti-gastric ulcer activity was evaluated and confirmed using mice model of acute alcoholic gastric ulcer. The experiment confirmed that GRR-CDs were the spherical structure with a large number of active groups on the surface and their particle size ranged from 2 to 10 nm. GRR-CDs had no toxicity to RAW264.7 cells at concentration of 19.5 to 5000 μg/mL and could reduce the oxidative damage of gastric mucosa and tissues caused by alcohol, as demonstrated by restoring expression of malondialdehyde, superoxide dismutase and nitric oxide in serum and tissue of mice. The results indicated the explicit anti-ulcer activity of GRR-CDs, which provided a new insights for the research on effective material basis of GRR.

scholarly journals Enhanced Photocatalytic Activity of CuWO4 Doped TiO2 Photocatalyst Towards Carbamazepine Removal under UV Irradiation

Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 25
Author(s):  
Chukwuka Bethel Anucha ◽  
Ilknur Altin ◽  
Emin Bacaksız ◽  
Tayfur Kucukomeroglu ◽  
Masho Hilawie Belay ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Pure Tio2 ◽  
Component Part ◽  
Energy Yield ◽  
Mechanical Agitation ◽  
X Ray

Abatement of contaminants of emerging concerns (CECs) in water sources has been widely studied employing TiO2 based heterogeneous photocatalysis. However, low quantum energy yield among other limitations of titania has led to its modification with other semiconductor materials for improved photocatalytic activity. In this work, a 0.05 wt.% CuWO4 over TiO2 was prepared as a powder composite. Each component part synthesized via the sol-gel method for TiO2, and CuWO4 by co-precipitation assisted hydrothermal method from precursor salts, underwent gentle mechanical agitation. Homogenization of the nanopowder precursors was performed by zirconia ball milling for 2 h. The final material was obtained after annealing at 500 °C for 3.5 h. Structural and morphological characterization of the synthesized material has been achieved employing X-ray diffraction (XRD), Fourier transform infra-red (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) N2 adsorption–desorption analysis, Scanning electron microscopy-coupled Energy dispersive X-ray spectroscopy (SEM-EDS), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectroscopy (UV-vis DRS) for optical characterization. The 0.05 wt.% CuWO4-TiO2 catalyst was investigated for its photocatalytic activity over carbamazepine (CBZ), achieving a degradation of almost 100% after 2 h irradiation. A comparison with pure TiO2 prepared under those same conditions was made. The effect of pH, chemical scavengers, H2O2 as well as contaminant ion effects (anions, cations), and humic acid (HA) was investigated, and their related influences on the photocatalyst efficiency towards CBZ degradation highlighted accordingly.

scholarly journals Synthesis of Novel Arginine-Based Flame Retardant and Its Application in Lyocell Fabric

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3588
Author(s):  
Jiayi Chen ◽  
Yansong Liu ◽  
Jiayue Zhang ◽  
Yuanlin Ren ◽  
Xiaohui Liu
Keyword(s):  
Fourier Transform ◽  
Heat Release ◽  
Flame Retardant ◽  
Photoelectron Spectroscopy ◽  
Fourier Transform Infrared ◽  
Ftir Analysis ◽  
Excellent Thermal Stability ◽  
X Ray ◽  
Cone Calorimeter Test ◽  
Before And After

Lyocell fabrics are widely applied in textiles, however, its high flammability increases the risk of fire. Therefore, to resolve the issue, a novel biomass-based flame retardant with phosphorus and nitrogen elements was designed and synthesized by the reaction of arginine with phosphoric acid and urea. It was then grafted onto the lyocell fabric by a dip-dry-cure technique to prepare durable flame-retardant lyocell fabric (FR-lyocell). X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) analysis demonstrated that the flame retardant was successfully introduced into the lyocell sample. Thermogravimetric (TG) and Raman analyses confirmed that the modified lyocell fabric featured excellent thermal stability and significantly increased char residue. Vertical combustion results indicated that FR-lyocell before and after washing formed a complete and dense char layer. Thermogravimetric Fourier-transform infrared (TG-FTIR) analysis suggested that incombustible substances (such as H2O and CO2) were produced and played a significant fire retarding role in the gas phase. The cone calorimeter test corroborated that the peak of heat release rate (PHRR) and total heat release (THR) declined by 89.4% and 56.4%, respectively. These results indicated that the flame retardancy of the lyocell fabric was observably ameliorated.

scholarly journals Study of the Effect of TiO2 Layer on the Adsorption and Photocatalytic Activity of TiO2-MoS2 Heterostructures under Visible-Infrared Light

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
N. Cruz-González ◽  
O. Calzadilla ◽  
J. Roque ◽  
F. Chalé-Lara ◽  
J. K. Olarte ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Nitrogen Adsorption ◽  
High Photocatalytic Activity ◽  
Infrared Light ◽  
Polluted Water ◽  
Light Spectrum ◽  
X Ray

In the last decade, the urgent need to environmental protection has promoted the development of new materials with potential applications to remediate air and polluted water. In this work, the effect of the TiO2 thin layer over MoS2 material in photocatalytic activity is reported. We prepared different heterostructures, using a combination of electrospinning, solvothermal, and spin-coating techniques. The properties of the samples were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), nitrogen adsorption-desorption isotherms, UV-Vis diffuse reflectance spectroscopy (UV-Vis-DRS), and X-ray photoelectron spectroscopy (XPS). The adsorption and photocatalytic activity were evaluated by discoloration of rhodamine B solution. The TiO2-MoS2/TiO2 heterostructure presented three optical absorption edges at 1.3 eV, 2.28 eV, and 3.23 eV. The high adsorption capacity of MoS2 was eliminated with the addition of TiO2 thin film. The samples show high photocatalytic activity in the visible-IR light spectrum.

scholarly journals Green Synthesis of Feather-Shaped MoS2/CdS Photocatalyst for Effective Hydrogen Production

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Yang Liu ◽  
Hongtao Yu ◽  
Xie Quan ◽  
Shuo Chen
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Production ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance ◽  
Sulfur Source ◽  
X Ray ◽  
Transmission Electron ◽  
Microscopy Images ◽  
Effective Hydrogen ◽  
Better Than

MoS2/CdS photocatalyst was fabricated by a hydrothermal method for H2production under visible light. This method used low toxic thiourea as a sulfur source and was carried out at 200°C. Thus, it was better than the traditional methods, which are based on an annealing process at relatively high temperature (above 400°C) using toxic H2S as reducing agent. Scanning electron microscopy and transmission electron microscopy images showed that the morphologies of MoS2/CdS samples were feather shaped and MoS2layer was on the surface of CdS. The X-ray photoelectron spectroscopy testified that the sample was composed of stoichiometric MoS2and CdS. The UV-vis diffuse reflectance spectra displayed that the loading of MoS2can enhance the optical absorption of MoS2/CdS. The photocatalytic activity of MoS2/CdS was evaluated by producing hydrogen. The hydrogen production rate on MoS2/CdS reached 192 μmol·h−1. This performance was stable during three repeated photocatalytic processes.

scholarly journals Study on Synthesis and Photocatalytic Activity of Porous Titania Nanotubes

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Huang Liu ◽  
Yanhua Zhang ◽  
Hongtao Yang ◽  
Wei Xiao ◽  
Lanlan Sun
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Filter Paper ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Cellulose Nanofibers ◽  
Titania Nanotubes ◽  
Tetrabutyl Titanate ◽  
X Ray ◽  
Porous Titania

Using the common natural cellulose substance (filter paper) and triblock copolymer (Pluronic P123) micelles as dual templates, porous titania nanotubes with enhanced photocatalytic activity have been successfully synthesized through sol-gel methods. Firstly, P123 micelles were adsorbed onto the surfaces of cellulose nanofibers of filter paper, followed by hydrolysis and condensation of tetrabutyl titanate around these micelles to form titania layer. After calcination to remove the organic templates, hierarchical titania nanotubes with pores in the walls were obtained. The sample was characterized by X-ray diffraction pattern (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption/desorption, Fourier Transform Infrared Spectroscopy (FT-IR), Ultraviolet-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS), and X-ray photoelectron spectroscopy (XPS). As compared with commercial P25 catalyst, the porous titania nanotubes prepared by this method displayed significantly enhanced photocatalytic activity for degrading methyl orange under UV irradiation. Within 10 minutes, the porous titania nanotubes are able to degrade over 70% of the original MO, while the value for the commercial Degussa P25 is only about 33%.

Use of anti-solvent to enhance thermoelectric response of hybrid-halide perovskite thin films

2022 ◽  
Author(s):  
Shrikant SAINI ◽  
Izuki Matsumoto ◽  
Sakura Kishishita ◽  
Ajay Kumar Baranwal ◽  
Tomohide Yabuki ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Cost Effective ◽  
Performance Tuning ◽  
Charge Carrier Density ◽  
X Ray ◽  
Thermoelectric Energy Harvesting ◽  
Halide Perovskite

Abstract Hybrid halide perovskite has been recently focused on thermoelectric energy harvesting due to the cost-effective fabrication approach and ultra-low thermal conductivity. To achieve high performance, tuning of electrical conductivity is a key parameter that is influenced by grain boundary scattering and charge carrier density. The fabrication process allows tuning these parameters. We report the use of anti-solvent to enhance the thermoelectric performance of lead-free hybrid halide perovskite, CH3NH3SnI3, thin films. Thin films with anti-solvent show higher connectivity in grains and higher Sn+4 oxidation states which results in enhancing the value of electrical conductivity. Thin films were prepared by a cost-effective wet process. Structural and chemical characterizations were performed using x-ray diffraction, scanning electron microscope, and x-ray photoelectron spectroscopy. The value of electrical conductivity and the Seebeck coefficient were measured near room temperature. The high value of power factor (1.55 µW/m.K2 at 320 K) was achieved for thin films treated with anti-solvent.

Oxidation of Alloy-X in Subcritical, Transition, and Supercritical Water

CORROSION ◽  
10.5006/3881 ◽  
2021 ◽  
Author(s):  
Zachary Karmiol ◽  
Dev Chidambaram
Keyword(s):  
Supercritical Water ◽  
Photoelectron Spectroscopy ◽  
Focused Ion Beam ◽  
Elevated Temperatures ◽  
Subcritical Water ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Based Superalloy ◽  
Before And After

This work investigates the oxidation of a nickel based superalloy, namely Alloy X, in water at elevated temperatures: subcritical water at 261°C and 27 MPa, the transition between subcritical and supercritical water at 374°C and 27 MPa, and supercritical water at 380°C and 27 MPa for 100 hours. The morphology of the sample surfaces were studied using scanning electron microscopy coupled with focused ion beam milling, and the surface chemistry was investigated using X-ray diffraction, Raman spectroscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy before and after exposure studies. Surfaces of all samples were identified to comprise of a ferrite spinel containing aluminum.

scholarly journals Hydrothermal Synthesis of Iodine-Doped Nanoplates with Enhanced Visible and Ultraviolet-Induced Photocatalytic Activities

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Jiang Zhang ◽  
Zheng-Hong Huang ◽  
Yong Xu ◽  
Feiyu Kang
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Oxygen Vacancies ◽  
Diffuse Reflectance Spectroscopy ◽  
Synergetic Effect ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Photocatalytic Activities

The iodine-doped Bi2WO6(I-BWO) photocatalyst was prepared via a hydrothermal method using potassium iodide as the source of iodine. The samples were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. The photocatalytic activity of I-BWO for the degradation of rhodamine B (RhB) was higher than that of pure BWO and I2-BWO regardless of visible light (>420 nm) or ultraviolet light (<400 nm) irradiation. The results of DRS analysis showed that the I-BWO and I2-BWO catalysts had narrower band gaps. XPS analysis proved that the multivalent iodine species including I0and were coadsorbed on the defect surface of Bi2WO6in I-BWO. The enhanced PL intensity revealed that a large number of defects of oxygen vacancies were formed by the doping of iodine. The enhanced photocatalytic activity of I-BWO for degradation of RhB was caused by the synergetic effect of a small crystalline size, a narrow band gap, and plenty of oxygen vacancies.

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