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In this study, facile solid-state CdS quantum dots (QDs) supported MoO3/g-C3N4 nanostructure photocatalysts were prepared via an innovative in-situ deposition protocol with consecutive ionic layer adsorption and reaction. The CdS QDs-anchored MoO3/g-C3N4 heterostructure photocatalysts demonstrated enhanced visible-light absorption capacity, which was realized by the quantum confinement of the CdS QDs. The maximum photocatalytic hydrogen (H2) production rate with the CdS QDs-anchored MoO3/g-C3N4 heterostructure photocatalysts reached 294.32 μmol g− 1 h−1, which was 76.84, 215.21, 27.12, and 3.64 folds superior as compare to bare g-C3N4, MoO3, CdS, and MoO3/g-C3N4 catalysts, respectively. The enriched photocatalytic performance was mainly credited to the high surface area and MoO3 with oxygen vacancies (OV), ultra-thin g-C3N4 and high optical adsorption ability of CdS QDs. Thus, forming a dual Z-scheme system in the CdS QDs-supported MoO3-OV/g-C3N4 nanostructures not only facilitated efficient interfacial charge transfer but also preserved the robust redox ability of the photoinduced electrons and holes.

Carbon steel coupons are used to characterize inhibition efficiency and surface properties for different Ficus racemosa leaf extract (FRLE) concentrations including 0, 500, 1000, 1500 and 2000 ppm in an aerated 0.1 M hydrochloric acid solution. The results indicate that carbon steel is significantly protected by FRLE and higher performances are reached with an increase in FRLE concentration up to 1500 ppm (93.11 ± 1.99%). Additionally, the addition of 2000 ppm FRLE reduced inhibition performance (88.86 ± 2.15%) due to high inhibition concentrations that could impede the formation of a solid protective film. This also demonstrates that the corrosion of steel is probably retarded via the formation of a protective film which is reinforced by FRLE concentration and exposure time due to the continuous adsorption of FRLE inhibitor components at suitable concentrations. The quantum chemical calculations demonstrate a high binding energy between FRLE molecules and carbon steel and a good thermal stability of the adsorbent layer, as well as an electron abundance of the FRLE species. This could result in a much more compact solid protective layer that could hinder electrochemical corrosion when carbon steel is exposed in an aerated 0.1 M hydrochloric acid solution.

Additive manufacturing not only offers the ability of constructing complex structural components but also creating strong and more durable parts than any other existing fabrication methods. In addition, it opens a novel research direction in developing new materials specifically for additive manufacturing beside the current wrought and cast materials. The present research attempted to produce an aluminum–magnesium–scandium alloy for selective laser melting. Nearly full dense samples were achieved through the process optimization. Significantly high mechanical strengths as-printed condition (450 MPa) with high ductility (26%) were obtained. This could be explained through super-fine and hierarchically graded microstructure and the formation of rod bundles in the melt-pool.

The integration of multi-dimensional functional materials of precious-metal-free semiconductor photocatalysts is of considerable significance for the conversion of solar energy to other forms of energy. Advanced materials for hydrogen-gas generation from water splitting using photonic energy have gained importance in modern science technology owing to the depletion of fossil fuels. In this study, an integrated ternary Na2Ti3O7/V2O5/g-C3N4 composite was prepared, and its performance in both hydrogen production from water splitting and organic-dye degradation was evaluated under visible-light illumination. Furthermore, the electrochemical behavior of Na2Ti3O7/V2O5/g-C3N4 was studied. The structural, morphological, and chemical properties of the prepared ternary composites were thoroughly analyzed through various analytical techniques. The ternary composite of Na2Ti3O7/V2O5/g-C3N4 exhibited admirable photocatalytic kinetics for H2 production and dye degradation, which was three times greater than that of Na2Ti3O7/V2O5. Moreover, the rate of RhB dye degradation by Na2Ti3O7/V2O5/g-C3N4 was higher than that of the Na2Ti3O7/V2O5 catalyst under identical conditions.

In this work, we report a novel free-standing graphene (Gr) hybrid materials consisting of functionalized AuNPs sandwiched between two graphene sheets, where the film sensor formation is based on layer by layer deposition through vacuum filtration. The sensor offers highly conductivity, high sensing with short response time, high sensitivity, stability and life time durability. The construct of hybrid film favors the conducting pathways for charge transport and a decrease in charge transfer resistance is clearly observed through electrochemical study. The sensing experiments shows high sensitivity of 5 × 10−4 kPa−1 with short response time of

The vascular endothelial growth factor 165 (VEGF165) is a quintessential biomarker in cancers. An easy and precise tool for the early detection of malignancies is required for rapid care and metastasis prevention. Cobalt-based metal–organic framework (Co-BTC-GO-MOF) nanoparticles have been used as a signal carrier for the anti-VEGF165 signaling antibody. Cobalt-based MOF was synthesized using cobalt (Co), benzene-1,3,5-tricarboxylate (BTC), and graphene oxide (GO) applying a hydrothermal method. Structure, compositions, size and morphology of the qualified sensor are determined by using distinctive analytical techniques. The Co-MOF nanoparticles are found to be thermostable, as revealed by thermal stability assay. The strategy utilises an impedimetric and differential pulse voltammetry (DPV) techniques in the presence of the [Fe(CN)6]3−/4− redox system. Compared to earlier results, this assay resulted in higher sensitivity with the limit of detection (LOD) found to be 5.23 pM in a 0.01 M buffer solution of pH 7.4 using linear scale voltammetry at room temperature. The resulting Co-BTC-GO-MOF immunosensor shows high responsiveness and selectivity in detecting VEGF165 in real-time serum samples of cancer patients. The electrochemical performance studies confirm that the intended proposed immunosensor could pave the way for the future advancement of high-performance, sensitive, reproducible and robust immunosensors for the cost-effective and initial phase detection of cancer in the future.

In this study, strontium is used as an alloying element for improving the pitting resistance of Mg-5Al-4Sn based alloys in an alkaline solution. Potentiodynamic polarization measurements suggest that the addition of strontium increases the robustness of the pitting resistance as a result of the higher pitting potential and wider range of passive potential. Electrochemical impedance spectroscopy (EIS) confirms the formation of a solid passive film on the alloy surface due to a significant increase in the passive film and the charge transfer resistance, as well as lower film and double layer constant phase element magnitude values. Additionally, the potentiostatic polarisation results also show a lower passive current density and passive film stability, resulting in an increase in the breakdown time when the amount of strontium added to the alloy increases from 0.0 to 1.0 wt%. Furthermore, the scanning electron microscopy results indicate that insignificant corrosion is observed on alloy specimens containing strontium, whereas there is fierce corrosion on alloy based surfaces. This robust corrosion resistance could be attributed to the α-grain reduction and refined precipitates at the alloy grain boundaries, resulting in promoted formation of the passive film which is formed from a mixture of magnesium, aluminum and tin oxides/hydroxides, as confirmed by the X-ray photoelectron spectroscopy results.

Aluminum and its alloys have prompted significant development in several industrial fields. However, aluminum is typically very difficult to weld and sometimes generates undesirable formations during various processes. Therefore, the properties of aluminum must be thoroughly investigated to improve its applicability to various engineering problems. In this study, Al-xMg alloys with x = 0, 2, and 4 wt% were successfully formed using a hot extrusion method and characterized using various electrochemical and surface analysis techniques following immersion in a 0.1 M Na2SO4 + 0.01 M NaCl solution. The results indicate that an increase in Mg content in Al-based alloys leads to better pitting resistance. This could be a result of significant changes in grain size and passive film formation on alloy surfaces, which lead to superior physical properties. Keywords: Alloys, Extrusion, Grain size, Pitting corrosion, Electrochemistry

Vật liệu cellulose và nickel (Ni/cellulose) được ứng dụng tham gia vào phản ứng xúc tác điện hóa đối với ethanol. Cellulose được tổng hợp từ phế thải của nông nghiệp như vỏ cam ở miền nam Việt Nam thông qua phương pháp thủy nhiệt trong môi trường kiềm. Nickel đã được kết tủa thành công trên bề mặt cellulose bằng cách khử hydrazine hydrate. Hình thái học, tham số mạng và trạng thái bề mặt của hỗn hợp Ni/cellulose được xác định bằng phương pháp nhiễu xạ tia X (XRD), phổ hồng ngoại biến đổi Fourier (FTIR), kính hiển vi điện tử quét (SEM). Hoạt tính điện hóa của xúc tác Ni/cellulose cũng được khảo sát bằng phương pháp quét thế vòng tuần hoàn (cyclic voltammetry - CV), quét thế tuyến tính (linear sweep voltammetry – LSV) và chronoamperometry - CA. Kết quả đặc tính cho thấy các hạt Ni kích thước nano phân bố không đồng đều trên mạch cellulose, xúc tác Ni/cellulose cho thấy hoạt tính điện hóa cao và ổn định đối với quá trình điện hóa ethanol. Mật độ dòng điện cực đại của xúc tác Ni/cellulose là gần 1.2 mA.cm-2 khi xuất hiện 0,1M ethanol trong môi trường kiềm. Kết quả cho thấy rằng vật liệu Ni/cellulose hứa hẹn sẽ đóng gớp tích cực như tiếp cận mới cho lĩnh vực xúc tác điện hóa và pin nhiên liệu ethanol.

The corrosion inhibition mechanism of cerium hydroxycinnamate compounds has been studied and compared as an effective corrosion inhibitor for steel in an aqueous 0.6 M NaCl solution. Surface analysis results showed that the surface of steel coupons exposed to solutions containing cerium hydroxycinnamate compounds has less signs of corrosion attack due to a formation of the protective film, while the surface of mild steel coupons exposed to 0.6 M chloride solution without inhibitor additions was severely corroded due to pitting. Electrochemical results performed a good inhibition performance and information of the formed protective deposit that hinders the electrochemical corrosion reactions with a dominance of anodic inhibition mechanism. The results also indicated that the addition of cerium hydroxycinnamate compounds to 0.6 M NaCl solution could mitigate electrochemical corrosion reactions, reduce protective and double layer CPE magnitudes, and improve protective and charge transfer resistances. Furthermore, cerium 2-hydroxycinnamate showed better efficient corrosion inhibitor in comparison with cerium 4-hydroxycinnamate for steel in aqueous media containing 0.6 M chloride ion.

A combination of composites and metallic materials has been shown to be an effective way to modify the microstructure and thus enhance the corrosion properties. This study focuses on the development of a new aluminum alloy using Mg and AlN composite and the hot extrusion processing. The microstructures and electrochemical properties have been characterized using the advanced surface analysis and electrochemical techniques in a naturally-aerated 0.1 M chloride solution. Open circuit potential and potentiodynamic polarization results indicate that Mg and AlN composite additions could improve corrosion and pitting potentials as well as passive film quality formed on the alloy surface. Electrochemical impedance spectroscopy has confirmed that the addition of Mg and AlN composite also increases the passive film and charge transfer resistances, resulting in an improvement of passive film stability and pitting resistance. X-ray photoelectron spectroscopy suggests that Mg and AlN composite addition promotes the stable passive film formed on the aluminum alloy surfaces due to the existence of Mg oxides/hydroxides and AlN incorporating with Al oxides/hydroxides. The improved pitting resistance could be attributed to the reduction in the grain sizes and defects in the alloy matrix that are observed by electron backscatter diffraction and could directly relate to the alloy dissolution and passive film formation.

The vascular endothelial growth factor 165 (VEGF

In this study, the Respond Surface Method (RSM) is applied to optimize the performance of the new micro gas actuator of MIKRA for analysis of the SO2 fraction in the mixture of the CH4-SO2. The impacts of effective factors such as pressure of domain, mass concentration of SO2 and temperature difference of arms are investigated to offer optimum condition for the high precision measurement of the SO2 gas in the SO2-CH4 mixture. Also, the overall performance correlation of MIKRA is presented to reveal the maximum Knudsen force in different operating conditions. Obtained results show that growing the operating pressure from 300 Pa to 1000 Pa increases three times the value of Knudsen force and this elevates the precision of this micro gas actuator for sensing SO2 gas in the natural gas. According to our findings, reduction of the gap size from 10 μm to 30 μm declines the net Knudsen force more than 2 times at specific SO2 concentration of φ = 0.5 . Our results demonstrate that increasing the pressure enhances the precision of the SO2 detection in this micro sensor.

Objective:Cinnamic acid and its derivatives have a numerous potential applications in many different fields such as pharmacy, organic “building blocks”, and corrosion inhibitors.Method:It is well-known that Verley-Doebner modification is a high efficient method for the preparation of cinnamic acid derivaties, especially with the compounds containing electron-donating subtituents at para position in aromatic ring. In this paper, 4-ethoxy-cinnamic acid was synthesized according to Verley-Doebner reaction with the use of pyrine acting as catalyst and solvent. The effect of the β-alanine concentration on the conversion of the starting material of 4-ethoxy-benzaldehyde was thoroughly investigated using high performance liquid chromatography. The results showed that consuming of 8% of β-alanine would convert 100% of 4-ethoxy-benzaldehyde to 4-ethoxy-cinnamic acid.Result:The structure of the obtained 4-ethoxy-cinnamic acid was also confirmed using Fourier transform infrared spectroscopy, Raman spectroscopy, and Gas chromatography-Mass spectroscopy.Cinnamic acid and its derivatives have numerous potential applications in many different fields such as pharmacy, organic “building blocks”, and corrosion inhibitors. It is well-known that Verley-Doebner modification is a high efficient method for the preparation of cinnamic acid derivaties, especially with the compounds containing electron-donating subtituents at para position in aromatic ring. In this paper, 4-ethoxy-cinnamic acid was synthesized according to Verley-Doebner reaction with the use of pyrine acting as catalyst and solvent. The effect of the β-alanine concentration on the conversion of the starting material of 4-ethoxy-benzaldehyde was thoroughly investigated using high performance liquid chromatography. The results showed that consuming 8% of β-alanine would convert 100% of 4-ethoxy-benzaldehyde to 4-ethoxy-cinnamic acid. The structure of the obtained 4-ethoxy-cinnamic acid was also confirmed using Fourier transform infrared spectroscopy, Raman spectroscopy, and Gas chromatography-Mass spectroscopy.

A Mg-5Al alloy was processed using the friction stir welding (FSW) technique with traveling speeds ranging from 0 to 80 mm/min. The influence of the FSW-traveling speed on the prepared Mg-5Al alloy was examined using electrochemical and surface analysis techniques. The electrochemical tests revealed that an increasing FSW-traveling speed results in a significant improvement of the corrosion resistance, as characterized by the higher pitting potential and film and charge transfer resistances. The increased corrosion resistance was attributed to the enhanced refinement of the precipitates, grain refinement and increased homogeneity of the microstructure obtained with an increasing FSW-traveling speed.

An enhancement of tensile and compressive yield strengths, ultimate tensile and compressive strengths and hardness of extruded Mg-8Gd-4Y-0.5Zr have been achieved by alloying with 2 wt.% Zn. Corrosion resistance of the extruded Mg-8Gd-4Y-0.5Zr alloy in saline solutions is also improved by alloying with 2 wt.% Zn. These enhancements could be attributed to the suppression of Mg(Gd,Y) intermetallic phases and the inducement of MgZn precipitation in the Mg matrix along with grain refinement, resulting in an improvement of mechanical properties and corrosion resistance. In addition, an interaction of Zn oxide with Mg, Gd, Y, and Zr products serve as a corrosion barrier by alloying with Zn.

Yttrium 3-(4-nitrophenyl)-2-propenoate has been studied as an effective corrosion inhibitor for copper alloy in 0.1 M chloride solution. The results show that the surface of copper alloy coupons exposed to solutions containing 0.45 mM yttrium 3-(4-nitrophenyl)-2-propenoate had no signs of corrosion attack due to protective film formation, whereas the surface of copper alloy coupons exposed to non-inhibitor and lower concentrations of yttrium 3-(4-nitrophenyl)-2-propenoate containing solutions were severely corroded. A high inhibition performance is attributed to the forming protective inhibiting deposits that slow down the electrochemical corrosion reactions and mitigate corrosion by promoting random distribution of minor anodes.

The evolution of microstructure and texture for an extruded Mg-9Gd-4Y-0.6Zr alloy during static annealing was investigated. The grain growth, precipitation and texture modification were characterized by optical microscopy, scanning electron microscopy, transmission electron microscopy, XRD texture instrument and EBSD. The results show that the grain refinement at the initial stage of static annealing is caused by recrystallization. The intergranular deformation stimulates local precipitating, which in turn inhibits the recrystallization process. The texture analysis indicates that the hot extrusion produces the conventional basal fiber with {0001} // ED and the unusual prismatic fiber with c axis // ED. During static recrystallization, the grain nucleation weakens the prismatic fiber, while the grain growth strengthens it. A large number of plate phases precipitate at grain boundaries along with subgrain boundaries, which significantly inhibits the texture modification.

The corrosion behavior of extruded AZ61 magnesium alloy with different addition of yttrium ranging from 0 to 0.9 wt. % was investigated. The electrochemical techniques in naturally-aerated 0.01 M NaCl solution and the surface analyses are utilized. The electrochemical results show that the pitting potential, time to pitting initiation, film and charge transfer resistances of the AZ61 specimens increased with the increase of yttrium content. Surface analyses indicate that yttrium promotes the formation of passive films and the refinement of the precipitates and matrix grains.

For optimizing the performance of tungsten oxide (WOx)/c-Si heterojunction solar cells, it is important to understand the carrier transport process within the device. Recently, several studies examined transport mechanisms; but yet reported not apparently. In this study, the fundamental carrier transport mechanisms in WOx/c-Si heterojunction solar cells and their effects on the device characteristics are investigated. Our results indicate that the trap-assisted-tunneling (TAT) process is the dominant carrier transport mechanism in the forward-bias voltage regime, while the generation of current in the space-charge region is dominant in the reverse-bias voltage regime. Interestingly, it was found that the hole-selective contact with lower oxygen-to-tungsten ratios, which is related to that of high trap densities, can assist the TAT process and increase the fill factor of the device regardless of the film conductivity. This finding is inconsistent with those of previous experiments but is consistent with those of previous simulations. Finally, this confirmation can help with optimization of WOx/c-Si heterojunction solar-cell efficiencies.

The development of corrosion inhibitors that could spontaneously adsorb immediately on the metal surfaces after they are damaged by electrochemical reactions would remarkably arise the improvement of cost-saving, durability and environmental impact of metals. The use of leaf materials for metal corrosion remains an important challenge due to the high corrosion protection, availability as natural materials, environmental friendly and low-cost. Herein, we report a Houttuynia cordata leaf extract as a green corrosion inhibitor that acts as a mixed type of inhibitor for steel in an aqueous 0.1 M hydrochloric acid solution. It also performs the high inhibition performance (up to 98.3% by adding 1500 ppm inhibitor), spontaneous uniform and smooth film formation of the steel surface and less corrosion attack when the H. cordata leaf extract is added to the aqueous hydrochloric acid solution. In contrast to the inhibited systems, uninhibited specimen is severely corroded at high corrosion rate, which is associated with a significant degradation of the entire steel surface. Additionally, investigation on good adhesion and thermal stability of the protective film, as well as enriched electron abundance of selected inhibitor species are performed via molecular dynamics simulation method. Furthermore, insights of corrosion, inhibition and spontaneous film formation mechanisms are also proposed and discussed in detail.

Unsteady treatment of PCM during converting from liquid to solid phase was scrutinized in this attempt. Not only solid fraction but also irreversibility and temperature were evaluated. Fins with V shape were connected to inner wall and both outer and inner surfaces were maintained at cold temperature. Besides, nanotechnology was hired to augment conduction mode. When L = 1.8, changes the shape of Nano powders from m = 3 to 5.7 makes the time declines about 5.38%. Also, switching from sphere to cylinder shapes results in 3.75% reduction in required time. As longer find employed, the role of m on process did not changes anymore. Needed time for Brick shape of nanoparticles is 1.015 times lower than that of sphere shape. Growth of L from 1.8 to 2.26 leads to reduction of time about 1.2% and 1.18% for m = 3 and 5.7, respectively. Augmenting φ from 0 to 0.04 when L = 2.26, makes the time to reduces about 20.98%.

Current simulation provided analysis of discharging process inside a tank with circular and wavy cold surfaces. To improve the discharging, nano powders with various diameters were utilized and influences of amplitude of wavy wall has been scrutinized. Galerkin approach for simulation of equations in which gravity impact has been neglected and for better simulation of process, time dependent grid has been utilized. Energy of system has direct relation with temperature and its profile has reduction tendency with time. Influence of dp become less effective with reduce of A. Solidification time reduces about 19.89% and 18.85% with rise of dp from 30 to 40 nm, when A = 0.5 and 0.1, respectively. Greatest influence of A occurs when dp equals to 40 nm and 1.42% reduction in time occurs with rise of A when dp = 40 nm. For scrutinized geometry, minimum time for solidification duration is 152.99 s which is achieved when A = 0.5 and dp = 40 nm.

The cavity flame holder is a conventional technique for efficient fuel mixing and auto-ignition inside the Scramjet engine. In this study, a computational method is applied to study the impact of the wedge shock generator on the fuel mixing performance inside the combustor at the supersonic flow of M=4. The main focus of the current work is to compare the vortex structure formed inside the cavity in various conditions. To perform simulations, a three-dimensional model with a structure grid is produced to fine reliable solution for our study. To capture the real flow structure, the SST turbulence model is applied for obtaining viscosity. The obtained results demonstrate that the presence of the wedge shock generator increase the mainstream entrains into the cavity. This declines the temperature inside the cavity and strengthens the fuel mixing rate which is highly significant for the efficient combustion process within the scramjet engine. According to our findings, secondary circulation weakens by the amplification of the oblique shock.

To gain high hardness, good thermal stability and corrosion resistance, multicomponent TiAlSiN coating has been developed using different deposition methods. In this study, the influence of Al and Si on the electrochemical properties of TiN-coated 316L stainless steel as bipolar plate (BP) materials has been investigated in simulated proton exchange membrane fuel cell environment. The deposited TiN, TiAlN and TiAlSiN possess high hardness of 23.9, 31.7, 35.0 GPa, respectively. The coating performance of the TiN coating is enhanced by Al and Si addition due to lower corrosion current density and higher R coating and R ct values. This result could be attributed to the formation of crystalline-refined TiN(200), which improves the surface roughness, surface resistance, corrosion performance, and decreased passive current density.

Five types of Mg–5Al alloys with different weight percentages of Zn ranging from 0 to 4 wt.% were examined using electrochemical techniques and surface analysis. The electrochemical results indicated that the Mg–5Al alloys containing Zn have a lower corrosion and hydrogen evolution rates than the Mg–5Al based specimens with a decrease of value being observed with the decrease in Zn content. Zn addition induced the precipitation of Mg–Al and Mg–Zn phases in the Mg matrix along with grain refinement and increased an interaction of Zn oxide with Mg and Al products serving as a corrosion barrier.

An improved photocatalytic activity of semiconductor materials using incorporation of the noble metals such as Ag, Au, and Pt is a promising technology. In this study, Ag nanoparticle-TiO2 nanotube structures (Ag-TNTs) have been investigated as a photocatalyst in different irradiation conditions using different characterization techniques. The results indicate that Ag nanoparticles dispersed uniformly on the TNTs’ surface without any change in TNTs’ morphology. In addition, Ag-TNTs exhibited lower photoactivity than the TNTs under UV irradiation. In contrast, Ag-TNTs increased the photoactivity in comparison with TNTs and the photocatalytic performance under sunlight irradiation. These phenomena could be contributed to the appearance of Ag nanoparticles on the nanotube surface.

The corrosion resistance of a multilayered (NiP-Pd-Au) coating with various thicknesses of palladium (Pd) interlayer deposited on copper by an electroless method was investigated using electrochemical techniques including potentiodynamic polarization and electrochemical impedance spectroscopy. In addition, the surface finish was examined by x-ray diffraction analysis and scanning electron microscopy, and the contact angle of the liquid–solid interface was recorded. The corrosion resistance of the copper substrate was considerably improved by Pd interlayer addition. Increase of the thickness of the Pd interlayer enhanced the performance of the Cu-NiP-Pd-Au coating due to low porosity, high protective efficiency, high charge-transfer resistance, and contact angle. These are attributed to the diffusion of layers in the Cu-NiP-Pd-Au coating acting as a physical barrier layer, leading to the protection provided by the coating.