Typical X-ray Diffraction Pattern Research Articles

Changes in structure, physicochemical properties and in vitro digestibility of quinoa starch during heat moisture treatment with hydrogen-infused and plasma-activated waters

In this study, comparative effect of heat moisture treatment (HMT) with distilled, hydrogen-infused and plasma-activated waters on the structure, physicochemical properties and in vitro digestibility of quinoa starch (QS) was investigated. To our knowledge, this study is the first to apply hydrogen-infused water to starch modification. The surface of HMT-modified samples was much rougher than that of native QS. HMT did not change the typical “A”-type X-ray diffraction pattern of QS but it increased its relative crystallinity. Meanwhile, amylose content, gelatinization temperature and water absorption capacity of QS significantly increased, whereas viscosity and swelling power markedly decreased. The rapidly digestible starch level of HMT-treated samples was significantly lower than that of native QS, and the resistant starch content markedly increased. These alterations were dependent on treatment moisture level. Furthermore, compared to distilled water, the HMT with hydrogen-infused and plasma-activated waters induced much more extensive effect on above properties, and the sample treated with plasma-activated water had the highest extent due to the acidic or alkaline environment and reactive oxygen and nitrogen species. These results identified that the combination of HMT with hydrogen-infused or plasma-activated water was a novel strategy to improve the thermal stability and functionality of quinoa starch.

Synthesis of Zeolite from Fly Ash and Bottom Ash and Application for Biodiesel Transesterification

Burning coal in a Coal-Fired Power Plant produces by-products like fly ash and bottom ash. Zeolite synthesized from the ash in Teluk Sirih Coal-Fired Power Plant was applied as a catalyst in the biodiesel transesterification reaction. Zeolite synthesis used the hydrothermal method with acid pretreatment. The operating conditions for fly ash zeolite are a 2.4-molar ratio SiO2/Al2O3 and a crystallization time of 6 hours. The bottom ash zeolite used a 2.0-molar ratio SiO2/Al2O3 and a crystallization time of 8 hours. The performance test of the synthesized catalyst was carried out in the transesterification reaction using waste cooking oil as a raw material with a free fatty acid content of 0.7%. The synthesized catalyst was characterized using x-ray diffraction, scanning electron microscope, and Bruneuer-emmet-teller. The biodiesel with the highest yield was analyzed based on SNI 7182: 2015. The synthesis results of the catalyst produced type A zeolite, shown by the typical X-ray diffraction pattern and supported by the morphological test results using a cube-shaped. The surface area of zeolite fly ash and bottom ash is 12.87 m2/g and 5.13 m2/g. The test showed fly ash zeolite had the highest biodiesel yield of 89.66%. Based on the characterization using SNI 7182: 2015, the color and free glycerol met the standards, while density 40 ˚C, kinematic viscosity 40 ˚C, acid number, total glycerol, methyl ester content, and water content did not meet the standards.

Green Synthesis of Silver Nanoparticles using Coriandrum sativum and Murraya koenigii Leaf Extract and its Thrombolytic Activity.

Plants have been used for ages in traditional medicine, and it is exciting to perceive how recent research has recognized the bioactive compounds liable for their beneficial effects. Green synthesis of metal nanoparticles is a hastily emergent research area in nanotechnology. This study describes the synthesis of silver nanoparticles (AgNPs) using Coriandrum sativum and Murraya koenigii leaf extract and its thrombolytic activity. The aim of the study was to determine the clot lysis activity of Coriandrum sativum and Murraya koenigii synthesized silver nanoparticles. Leaves of Coriandrum sativum and Murraya koenigii were collected. Methanolic extraction of the plant sample was done through a Soxhlet extractor. The methanolic extract obtained from both the leaves was subjected to GC-MS analysis. The synthesized NPs from leaf extracts were monitored for analysis, where the typical X-ray diffraction pattern and its diffraction peaks were identified. 3D image of the NPs was analysed by Atomic Force Microscopy. The surface charge of nanoparticles was identified by Zeta potential. The Clot lysis activity of Coriandrum sativum and Murraya koenigii synthesized silver nanoparticles were analysed by the modified Holmstorm method. The thrombolytic property of the methanolic extract of plants Coriandrum sativum showed clot lysis activity at 2.5 mg/mL with 45.99% activity, and Murraya koenigii extract with 66.56% activity. The nanoparticles (Nps) from Coriandrum sativum showed clot lysis activity at 2.5 mg/mL with 58.29% activity, and NPs from Murraya koenigii with 54.04% activity. Coriandrum sativum in GC-MS exhibited 3 peaks, whereas Murraya koenigii extract showed five peaks with notable bioactive compounds. These NPs were further used for biomedical applications after being fixed by an organic encapsulation agent. The present research reveals the usefulness of Coriandrum sativum and Murraya koenigii for the environmentally friendly manufacture of silver nanoparticles.

Order-disorder structural transition of Nd2(Zr1-xCex)2O7 pyrochlores prepared by auto-combustion method

A series of pyrochlore solid solutions with general formula Nd2(Zr1-xCex)2O7 were successfully synthesized by the glycine-nitrate process (GNP) auto-combustion method and then sintered at high temperature. The order-disorder structure of the as-prepared ceramic samples was systematically characterized by X-ray diffraction (XRD) and Raman spectroscopy. Rietveld refinements of the typical XRD patterns were performed using Full-prof software. XRD and Raman results confirmed a co-existence structure composed of ordered pyrochlore and disordered defect-fluorite structure for Nd2(Zr0.75Ce0.25)2O7 and Nd2(Zr0.7Ce0.3)2O7 samples. And Nd2Ce2O7 specimen presented as defect-fluorite structure with rare earth C-type microdomains in both XRD and Raman spectroscopy. The effect of 48f oxygen on phase transition was verified by XRD and Raman spectroscopy. The refined x-parameter of 48f oxygen reflected the phase transition of Nd2(Zr1-xCex)2O7 solutions from pyrochlore to fluorite structure. High resolution transmission electron microscope (HRTEM) images and selected area electron diffraction (SAED) analysis of transmission electron microscopy (TEM) proved the representative Nd2(Zr0.7Ce0.3)2O7 sample showed biphasic structure with pyrochlore and defect-fluorite structure SAED rings. Also, the C-type microdomain SAED rings of Nd2Ce2O7 structure was found by TEM analysis.

Electrospinning process of CuxCo3-xO4fibers (CCOFs): structural, surface morphology, optical and magnetic study

In this paper, CuxCo3-xO4 fibers (CCOFs) were successfully fabricated by the electrospinning of PVP/Co(CH3COO)2-Cu(CH3CO2)2 composite solution, followed by calcinations. The CCOFs samples were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR), diffuse reflectance spectroscopy (DRS), and vibrating sample magnetometer (VSM).The structural analysis of the obtained samples, verified by XRD analysis indicates the growth of well-crystalline Cu0.72Co2.28O4 with a cubic spinel structure. Also, typical X-ray diffraction pattern shows formation of the second tenorite phase of CuO, which substantially influenced the structural, morphology, chemical, optical, and magnetic properties of the CCOFs.

Chemical Composition, Functional and Pasting Properties of Kersting’s Groundnut (Kerstingiella geocarpa Harms) Flour and Starch

The chemical composition, functional and pasting properties of kersting’s groundnut ( Kerstingiella geocarpa ) flour and starch were studied. Kersting’s groundnut flour had 4.75 % moisture, 2.43 % crude fat, 23.0 % crude protein, 2.47 % ash, 1.69 % crude fibre and 65.7 % carbohydrate. Starch yield was 34.0 %. Isolated starch had reduced ash, crude fibre and crude protein contents when compared with the flour. Higher water and oil absorption capacities values were obtained for the flour in comparison with the starch. The swelling power and solubility of both flour and starch measured from 55 to 95 o C at 10 o C interval increased as the temperature increased. The pasting viscosities of the flour were lower than that of the starch. Bean starch granules were predominantly oval to kidney shaped, with granule width between 9 and 24µm and length between 10 and 45µm. Kersting’s groundnut starch showed the “C” type x-ray diffraction pattern, characterized by a strong peak at 5.77, 5.12, 3.83 and a medium peak at 4.64 Å. Keywords: Kersting’s groundnut, flour, starch, amylose, pasting properties DOI: 10.7176/FSQM/115-04 Publication date: May 31 st 2022

New Cage-Like Cerium Trihydride Stabilized at Ambient Conditions

New Cage-Like Cerium Trihydride Stabilized at Ambient Conditions

Preparation and Characteristics of Wet-Spun Filament Made of Cellulose Nanofibrils with Different Chemical Compositions.

In this study, wet-spun filaments were prepared using lignocellulose nanofibril (LCNF), with 6.0% and 13.0% of hemicellulose and lignin, respectively, holocellulose nanofibril (HCNF), with 37% hemicellulose, and nearly purified-cellulose nanofibril (NP-CNF) through wet-disk milling followed by high-pressure homogenization. The diameter was observed to increase in the order of NP-CNF ≤ HCNF < LCNF. The removal of lignin improved the defibrillation efficiency, thus increasing the specific surface area and filtration time. All samples showed the typical X-ray diffraction pattern of cellulose I. The orientation of CNFs in the wet-spun filaments was observed to increase at a low concentration of CNF suspensions and high spinning rate. The increase in the CNF orientation improved the tensile strength and elastic modulus of the wet-spun filaments. The tensile strength of the wet-spun filaments decreased in the order of HCNF > NP-CNF > LCNF.

Tuning upconversion emissions of Ho&lt;sup&gt;3+&lt;/sup&gt; through changing excitation conditions

The upconversion (UC) emission properties of rare-earth ions are not only dependent on the host materials, but also relate to the excitation conditions. In this work, taking the Ho&lt;sup&gt;3+&lt;/sup&gt; ions for example, upconversion emission properties are studied in two NaYF&lt;sub&gt;4&lt;/sub&gt; and LiYF&lt;sub&gt;4&lt;/sub&gt; fluoride microcrystals through changing excitation conditions, namely the excitation power and the sample environment. The NaYF&lt;sub&gt;4&lt;/sub&gt;:20%Yb&lt;sup&gt;3+&lt;/sup&gt;/2%Ho&lt;sup&gt;3+&lt;/sup&gt; and NaYF&lt;sub&gt;4&lt;/sub&gt;:20%Yb&lt;sup&gt;3+&lt;/sup&gt;/2%Ho&lt;sup&gt;3+&lt;/sup&gt; microcrystal are synthesized by the hydrothermal method. The typical X-ray diffraction patterns of NaYF&lt;sub&gt;4&lt;/sub&gt;:20%Yb&lt;sup&gt;3+&lt;/sup&gt;/2%Ho&lt;sup&gt;3+&lt;/sup&gt; and LiYF&lt;sub&gt;4&lt;/sub&gt;:20%Yb&lt;sup&gt;3+&lt;/sup&gt;/2%Ho&lt;sup&gt;3+&lt;/sup&gt; microcrystal indicate that the prepared samples possess pure hexagonal phase NaYF&lt;sub&gt;4&lt;/sub&gt; structure and the pure tetragonal phase LiYF&lt;sub&gt;4&lt;/sub&gt; structure with high crystallinity, respectively. Most of NaYF&lt;sub&gt;4&lt;/sub&gt;:20%Yb&lt;sup&gt;3+&lt;/sup&gt;/2%Ho&lt;sup&gt;3+&lt;/sup&gt; microcrystals show uniform and regular rod shape with diameter and length of approximately 3 μm and 10 μm, respectively. Few rods with a length of approximately 5 μm are also observed. The LiYF&lt;sub&gt;4&lt;/sub&gt;:20%Yb&lt;sup&gt;3+&lt;/sup&gt;/2%Ho&lt;sup&gt;3+&lt;/sup&gt; microcrystals are all octahedral in shape with a smooth surface, the average size is around 10 μm. The spectral peculiarities of Ho&lt;sup&gt;3+&lt;/sup&gt; are investigated by using confocal microscopy equipment under near infrared 980 nm excitation. Beautiful patterns with different upconversion emissions of Ho&lt;sup&gt;3+&lt;/sup&gt; are discovered in single NaYF&lt;sub&gt;4&lt;/sub&gt; and LiYF&lt;sub&gt;4&lt;/sub&gt; microcrystal. As the excitation power increases, the upconversion emission of Ho&lt;sup&gt;3+&lt;/sup&gt; turns from green to pink in single NaYF&lt;sub&gt;4&lt;/sub&gt; microrods due to the cross-relaxation between Ho&lt;sup&gt;3+&lt;/sup&gt; and the energy back transfer from Ho&lt;sup&gt;3+&lt;/sup&gt; to Yb&lt;sup&gt;3+&lt;/sup&gt;. However, in single LiYF&lt;sub&gt;4&lt;/sub&gt;:Ho&lt;sup&gt;3+&lt;/sup&gt; microcrystal no similar phenomenon is observed. Nevertheless, when the powder of NaYF&lt;sub&gt;4&lt;/sub&gt; and LiYF&lt;sub&gt;4&lt;/sub&gt; microcrystals are excited by a 980 nm laser, increasing the power can turn the output colours of Ho&lt;sup&gt;3+&lt;/sup&gt; all green. Because particles outside the laser radiation are not directly covered by the laser, most of them are excited by the scattered light from the laser, and the actual excitation energy is low compared with at the center position. This result can be proved in the single NaYF&lt;sub&gt;4&lt;/sub&gt; and LiYF&lt;sub&gt;4&lt;/sub&gt; microcrystal under low excitation power. Thus, the results indicate that UC emission of rare-earth ions is controlled by changing the excitation condition. Using the new testing methods we can not only observe more interesting spectral phenomena, but also find a new way to further study its luminescence mechanism.

Phase-pure iron pyrite (FeS2) micro- and nano-sized crystals synthesized by simple one-step microwave-assisted hydrothermal method

Iron pyrite micro- and nano-sized crystals are desirable as active materials in lithium ion batteries and photovoltaics, and are particularly suitable for nanocrystal inks for roll-to-roll deposited or ink-jet printed solar cells. In this paper we report the synthesis of iron pyrite micro- and nano-sized crystals via simple and convenient green one-step microwave-assisted hydrothermal (M − H) process at relatively low growth temperatures, using commonly used precursors such as FeCl3, Na2S and S8 and. The structural, morphological and optical properties of the resulting nanostructured materials have been thoroughly investigated for two typical M − H growth temperatures. X-ray diffraction (XRD) pattern and Raman data revealed good crystalline quality for the as synthesized pyrite NCs. Typical XRD patterns show the dominant peaks which can be indexed as a pure cubic phase of FeS2, with lattice constant values close to the lattice parameters reported for FeS2, and in agreement with a stoichiometric pyrite phase. XRD and Raman analysis also confirm that no other impurities phases such as hexagonal FeS, marcasite, pyrrhotite, greigite, S or Fe–O compounds were detected, confirming the high purity of the synthesized iron pyrite nanocrystals. Various shapes of pyrite like quasi-cubic, cubic and flower-like FeS2 nanocrystals have been observed, which can be modulated by using different synthetic conditions. The sizes of the pyrite micro- and nanostructures were in the range of 150 nm to 1 μm as obtained. The present study indicates that the M − H method is a facile one-step way to obtain phase pure iron pyrite micro- and nano-sized crystals. Optical characterization confirms direct bandgap transitions (values of 2.61 eV and 2.55 eV for iron pyrite NCs samples hydrothermal grown at 130 °C and 160 °C, respectively), and indirect bandgap transitions (values of 1.19 eV and 1.52 eV for samples hydrothermal grown at 130 °C and 160 °C, respectively). Optical studies show high absorbance in the entire UV–Vis wavelength range making the as-synthesized pyrite nanocrystals potential candidate as absorber in nanoscale photovoltaic solar cells.

Hepatotoxicity and chromosomal abnormalities evaluation due to single and repeated oral exposures of chromium oxide nanoparticles in Wistar rats.

Metal oxide nanoparticles (NPs) have widespread uses ranging from nanoelectronics to nanotherapeutics. Because of their expanding industrial applications, a better understanding of their toxicity is needed. So far, limited reports are available on chromium oxide NPs (Cr2O3 NPs) toxicity. In this work, Cr2O3 NPs were synthesized and characterized in a sequential manner using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy. Dose- and time-dependent toxicity assessment of Cr2O3 NPs was carried out in Wistar rats by examining liver function biomarkers, tissue histopathology, micronuclei (MN) formation, and chromosomal aberrations (CAs) in bone marrow along with sperm abnormalities. The results of this study demonstrated typical XRD and FTIR patterns of Cr2O3 NPs with a size of approximately 23.47 nm. Animals exposed to Cr2O3 NPs, exhibited a significant increase in aspartate transaminase, alanine transaminase, alkaline phosphatase, gamma glutamyltransferase, and total bilirubin, signifying liver injury. Histopathology data also supported the marked alterations in the liver biochemistry of NPs-exposed animals. Further, an increase in the frequency of MN, CA, and sperm abnormalities suggested Cr2O3 NPs-mediated genotoxicity. It is, therefore, suggested that possible safety issues of Cr2O3 NPs should be addressed promptly with limited future use in occupational settings.

Catalytic pyrolysis of wood polymer composites over hierarchical mesoporous zeolites

Hierarchical zeolites have superior catalytic properties over purely microporous zeolites, leading to the enhanced diffusivity of molecules and strong acidity of the catalyst. In this study, hierarchical desilicated mesoporous ZSM-5 and Beta were prepared by the desilication of commercial microporous zeolites and applied to the catalytic pyrolysis of wood polymer composites. Hierarchical desilicated mesoporous ZSM-5 and Beta showed the typical X-ray diffraction patterns of microporous ZSM-5 and Beta with higher mesoporosity compared to the parent materials. The activity of the desilicated zeolites for the catalytic pyrolysis of wood polymer composites was evaluated using a thermogravimetric analysis and tandem micro reactor-gas chromatography/mass spectrometry. Among the catalysts tested, the lowest decomposition temperatures of wood polymer composites were observed using hierarchical desilicated mesoporous Beta followed by hierarchical desilicated mesoporous ZSM-5 and ZSM-5. This trend correlated well with the mesoporosity of the catalysts. The formation efficiency of hierarchical desilicated mesoporous ZSM-5 was highest followed by microporous ZSM-5, hierarchical desilicated mesoporous Beta, and Beta, indicating that in addition to mesoporosity, the shape selectivity induced by microporosity and strong acidity are important for the aromatization of pyrolysis vapors. In addition, the aromatic formation efficiency of the catalysts differed according to the properties of wood polymer composites. Compared to wood polymer composite 2, wood polymer composite 1 produced a larger quantity of aromatics during catalytic pyrolysis over all the catalysts at 500 °C owing to its higher polyethylene content. Both wood polymer composites exhibited a similar aromatic formation efficiency during catalytic pyrolysis at 600 °C because the diffusion hindering effect of polypropylene molecules to the catalyst pores was lower at the higher temperature.

Morphological, molecular evolution an in vitro digestibility of filamentous granules of banana starch during fruit development.

The development of starch granules of a banana cultivar (morado variety - Musa AAA subgroup Red dacca) from filamentous shape to semi-spherical and finally to oval shape, was studied. The purity of the extracted starch changed from 83.5% (6 weeks) to 95.4% (16 weeks). Impurities were ascribed to cellulosic and latex fractions responsible for the integrity of the pristine fruit. The amylose content was stabilized at about 29.6% after the 12th week. The thermal analysis showed that the gelatinization enthalpy increased from 5.0 to 11.2 J/g from the 6th to the 12th week, indicating an increased degree of internal molecular organization. The analysis of chain-length distribution and gel permeation chromatography, showing that the content of long chains (B1, B2, and B3+) increased with the development of the starch granule. Also, XRD analysis indicated that C- type X-ray diffraction pattern from early to later phases of development, although the relative crystallinity content increased from 19.3 to 23.5% after 16 weeks of development. FTIR revealed the formation of more ordered structures with the development time. In vitro digestion tests showed that the resistant starch fraction increased from 37.5% for week 6 to 55.5% for week 16.

The effect of target-substrate distance on surface morphology and properties of β-FeSi2 films prepared by pulsed laser deposition

Semiconducting iron disilicide (β-FeSi2) has been studied as thermoelectric materials, ferromagnetic materials and also optoelectronic materials. Since β-FeSi2 was successfully fabricated on Si (100) substrate by pulsed laser deposition (PLD) and followed annealing, we investigated the structural properties and crystallographic orientation of the films by X-ray diffraction (XRD) analysis. And also the scanning electron microscopy (SEM) was used to determine the structural properties and surface images of the films. Typical XRD patterns of the films show that no other diffraction peak can be found except β-FeSi2 and Si. The SEM results show that the films are composed of well-distributed grains, in the range of 100 - 200 nm in diameter. Atomic force microscope (AFM) and Fourier transform infrared (FTIR) spectroscopy were also used to characterize the fabricated β-FeSi2 films. We can find the roughness of the films and want to get the optimum conditions for the preparation of β-FeSi2 films on Si (100) substrate by PLD.

Synthesis, characterisation and dosimetric evaluation of MgB4O7 glass as thermoluminescent dosimeter

ABSTRACTThis study presumably reports the dosimetric properties of MgB4O7 glass system. A series of MgB4O7 glass samples with nominal compositions XMgO-(100-X) B2O3, with X = 35, 40 and 45 mol% was successfully synthesied using conventional melt quenching method. The presence of broad humps and absence of any sharp peak in typical X-ray diffraction patterns confirm the amorphous nature of the synthesised glass samples. Good glass forming ability, 0.55, of the mixture resulting in a glass with excellent glass stability, 1.4, was observed. Thermoluminescence glow curve was observed to be simple with a single well defined dosimetric peak around 200°C. The dose response was found to be linear from 6 µGy to 0.5 kGy when irradiated to Cs-137 gamma rays. Considerably satisfying thermoluminescent (TL) characteristics suggests that the MgB4O7 glass could be recommended as a TL dosimeter.

Changes in physicochemical properties of rice in response to high-temperature fluidized bed drying and tempering

ABSTRACTThe effects of high-temperature fluidized bed drying and tempering on pasting, gelatinization, crystalline and microstructural properties of long-grain Vietnamese rice cultivar A10 were examined. The freshly harvest paddy (33% wet basis) was dried at two drying temperatures (80 and 90°C) and two drying durations (2.5 and 3.0 min) using a custom-made lab-scale batch fluidized bed dryer. The dried rice was immediately tempered in sealed containers at 75 and 86°C for various tempering durations (0, 30, 40, and 60 min), followed by thin-layer drying at 35°C to reduce moisture level to 14% wet basis. Characterization of pasting, gelatinization, crystallinity, and microstructure of the dried rice was undertaken using rapid visco analyzer, differential scanning calorimetry, X-ray diffraction (XRD), and environmental scanning electron microscopy (ESEM), respectively. Pasting properties and gelatinization enthalpy decreased with higher drying temperature and longer tempering time while pasting and gelatinization temperatures increased. Degree of crystallinity changed slightly, however, a shift from A-type to A+V-type XRD pattern was observed. ESEM observation demonstrated some degree of collapse of the rice microstructure. The kernel integrity appeared to be enhanced by the gel network formed during partial gelatinization of starch, corroborating with the changes in pasting and gelatinization properties of the fluidized bed dried and tempered rice.

The Impact of Heat-Moisture Treatment on the Properties of Musa paradisiaca L. Starch and Optimization of Process Variables.

SUMMARYStarch stability under the processing conditions can be improved by modifying the granule structure using chemical and/or physical processes. The effect of heat-moisture treatment (HMT) on the physicochemical, morphological, pasting and thermal properties of green banana (Musa paradisiaca L.) starch was investigated. To analyze the changes in starch properties due to the combined effect of the process variables, time (h), moisture (%), and temperature (°C) were considered as independent variables using a central composite rotatable design. The native starch extracted using ammonium hydroxide as an antioxidant contained 80.4% total carbohydrates, 53.7% apparent amylose, 11.46% moisture, and other constituents (ash, protein, lipids), which accounted for less than 1%. The granule morphology was affected by the moisture and temperature used in HMT. A and B type X-ray diffraction patterns were observed in the native and modified starch. Mathematical models that describe the behaviour of modified starch properties as a function of the evaluated parameters were obtained. The variables time and temperature significantly affected the physicochemical, rheological and digestibility properties of starch.

Periodic voltammetry as a successful technique for synthesizing CdSe semiconductor films for photo-electrochemical application

Polycrystalline n-type CdSe thin films were deposited from aqueous bath at room temperature by periodic voltammetry for use in photo-electrochemical (PEC) solar cells. The influence of periodic scans on the functional properties of the chalcogenide films was thoroughly investigated through electron microscopy (SEM), X-ray diffraction (XRD), UV–visible spectrometry, and electrochemical techniques. The film thickness increases with the number of periodic scans, and the spectral measurements identify the optical band gap in the range 1.55–1.72 eV. The CdSe films show typical X-ray diffraction patterns of hexagonal crystal structure with particle size 20–30 nm, uniformly distributed throughout the matrix. PEC characteristics including photo-current density, conversion efficiency (η), fill factor (FF), and durability of the films were evaluated by the help of respective electrochemical techniques. The voltammetric cycle number was optimized which enable to identify the best CdSe film exhibiting photo-conversion efficiency of ~1% with minimum photocurrent decay.

Effects of bath pH on structural and electrochemical performance of Cu2O

Well-defined cuprous oxides (Cu2O) with different morphologies were successfully deposited on fluorine-doped tin oxide (FTO)-covered glass substrates by potentiostatic deposition. The effect of the pH values on the crystal morphologies of Cu2O was studied. The as-prepared products were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and UV-visible spectroscopy. The typical XRD patterns revealed that all Cu2O thin films were pure Cu2O phase. Different crystal morphologies of Cu2O could be obtained by varying pH. The Cu2O thin film was composed of a large number of star-like shape grains with the pH of 4.8. With a further increase of the pH, the Cu2O film showed the uniform dendrite morphology. LSV uncovered that E R (reduction potential of Cu2+ to Cu+) increased with the pH value enlargement. According to the EIS, diffusion coefficient of Cu2+ ion was reduced with the increase of the pH. The UV-vis absorption spectra revealed that the broad absorption peaks were from 300 to 500 nm and the evaluated band gap of the films was tunable in the range of 2.02–2.67 eV, with the variation of the pH values. According to the experiment and relevant literatures, the probable electrodeposition mechanism of the Cu2O was discussed.

Changes in physicochemical properties and in vitro digestibility of common buckwheat starch by heat-moisture treatment and annealing

Heat-moisture treatment (HMT) and annealing (ANN) were applied in the test to investigate how they can affect the physicochemical properties and in vitro digestibility of common buckwheat starch (CBS). In the practice, these two modification methods did not change typical ‘A’-type X-ray diffraction pattern of CBS. However, the gelatinization temperature, amylose content, and relative crystallinity increased and peak viscosity value and gelatinization enthalpy of CBS declined significantly. Both the solubility and swelling power, which were temperature dependent, progressively decreased along with the treatments. Remarkable increase in slowly digested starch and resistant starch level was found at the same time. Besides, the decreases of rapidly digested starch and total hydrolysis content by using HMT were greater than by using ANN. The results indicated that the ANN and HMT efficiently modified physicochemical properties and in vitro digestibility of CBS and were able to improve its thermal stability, healthy benefits and application value.