Materials Science for Energy Technologies最新文献

In this work, we report the fabrication of Ni and Cu tubular substrates and the synthesis of ZnO/CuO nanocomposite on them through the process of pulse electrodeposition. The systematic variation in CuO incorporation in the ZnO matrix and the processing technique were noticed to affect the structural, optical, photocatalytic, and anti-bacterial properties, which are well in accordance with the Field Emission-Scanning Electron Microscope, X-ray Diffraction, Fourier transform Infrared Spectroscopy and UV-Differential reflectance spectroscopy results. The remediation capabilities of the photocatalytic substrates were assessed through the degradation of methylene blue (MB) dye under solar irradiation. Optimized CuO incorporation within the ZnO nanorods resulted in the degradation of a 20 ppm of MB dye solution within 40 min and a higher concentration of 50 ppm within 95 min. The Ni and Cu electroformed tubes as substrates provided not only a reusable supporting frame but also a large surface-area for the growth of ZnO/CuO nanocomposite. The current study also dealt with the anti-bacterial efficacy of the above-mentioned substrates against E.coli. Hence, the Ni and Cu tubular thin film substrates with nanorods of ZnO/CuO composite were explored for the removal of organic as well as biological contaminants from waste water.

Continuous reactive distillation is one of the optimized methods for synthesis of C1-C6 esters industrially. The products of the reaction are difficult to be obtained in their pure states due to the presence of azeotropes in the system. The theme of the current work is to highlight the thermodynamic nature of the each C1-C6 alcohol/ester/water system independently and investigate the possible alternatives implemented for pure separation of ester and water. This work comprehensively reports reactive distillation study for continuous synthesis of C1-C6 esters and separation strategies implemented for alcohol/ester/water system in a compiled form. Presence of the azeotropes within the system components helps us in defining the feasible separation schemes to be applied in continuous study. Current work reports a systematic thermodynamic analysis of C1-C6 alcohol/esters/water mixture with help of residue curve map to investigate the complexity of the mixture and alternate configurations/ schemes implemented in continuous reactive distillation technology for enhanced conversion and purity of product streams.

Synthesis of ZnMnFe₂O₄ has been carried out using the co-precipitation method. The main precursors were stoichiometry with variations in the mass of Zn, Mn, and natural iron sand are 3:2:5 as sample 1, 3:2:4 as sample 2, and 3:4:3 as sample 3. The samples were calcination temperature of 500 °C for 2 h. The characterizations showed microstructure properties using X-ray diffraction (XRD), morphology properties using Scanning electron microscopy and energy dispersive X-ray (SEM-EDX), and magnetic properties tested using a Vibrating sample magnetometer (VSM), respectively. The crystal structure of ZnMnFe₂O₄ shows a cubic crystal structure as well as the main phase with no detectable impurities or other elements in the diffraction pattern. The effect of adding the composition of manganese to the sample shows that the value of the crystal diameter size increasing with the optimum value of 3.41 nm. The effect of material composition on the morphology of ZnMnFe₂O₄ is shown in the SEM-EDX results. As the composition of manganese and iron sand increases, the particle size distribution also increases with the optimum average particle size of 205–210 nm. The value of coercivity (Hc) of ZnMnFe₂O₄ decreases as the iron sand composition decreases and the manganese composition increases, but the value of the magnetic energy increases. The coercivity value is obtained with the optimum value of 415.78 Oe and ZnMnFe₂O₄ is to be potentially a magnetic permanent material.

Copper oxide (CuO) and zinc oxide (ZnO) were used as a matrix and reinforcement in the compression molding technique to produce conductive ceramic electrodes. CuO-ZnO-based ceramic composites were fabricated through conventional pressing with CuO:ZnO ratios of 75 %:25 %, 80 %:20 %, 85 %:15 %, 90 %:10 %, and 95 %:5 %. CuO and ZnO powders were sieved, dried, mixed, and then compressed at 300 MPa for 10 min to form a pellet before being burned for 3 h at 800, 900, and 1000 °C in a furnace. The sample's density, porosity, and electrical conductivity were measured. In addition, SEM, XRD analysis, and palm oil wastewater electrocoagulation were carried out. The optimal density value of CuO-ZnO-based ceramic composites ranged from 8.564 × 10³ to 9.205 × 10³ kg m⁻³. The optimal composition of the CuO:ZnO in the synthesized composites, namely 95 %:5 %, yielded the lowest porosity values (12.1 %-35.4 %), while the 75 %:25 % composition produced the highest porosity values (20.8 %–88.3 %). The optimum porosity value (12.1 %) was obtained by CuO:ZnO composite composition of 95 %:5 % with a sintering temperature of 1000 °C. This composite also generates a conductivity value of 1.019–16.897 S/m. The interaction of Zn²⁺ ions from ZnO crystals with CuO crystals increases the size of CuO and ZnO crystals, as determined by XRD analysis. Based on the findings of this study, CuO-ZnO ceramic electrodes could be utilized in industrial wastewater treatment as the water quality test result met the requirements of Minister of Environment Decree No. 51/MENLH/10/1995.

In just a few years, the worldwide scientific community has worked diligently to increase the photovoltaic conversion efficiency of perovskite solar cells from 3.8% to 25.7%. Due to its low stability and poor scalability, it still lags in commercial performance concerning the crystalline silicon solar cell. Most of the high-efficiency perovskite solar cells (PSC) reported in the literature are on a 0.01 cm² area, and the efficiency of PSC decreases with an increase in area. The maximum said stability to date is 10,000 h which is relatively low compared to crystalline silicon technology. This work discussed the causes of instability, degradation mechanism, scalable fabrication methods, and high-stability perovskite solar cell. It emphasised the need for setting up testing protocols for universal stability testing of perovskite solar cell technology. The study found that trap states in the absorber layer, hole transport layer (HTL), and electron transport layer (ETL) are the reason for lower stability. The lower dimension perovskite solar cell shows better stability compared to its 3D counterparts.

Agricultural waste is rich in organic matter and an important secondary source of phosphorus, which can be converted into valuable products through various technologies. Composting is an effective way to treat agricultural waste and further produce organic fertilizer, achieving waste minimization and stabilization. This paper reviews the current situation of agricultural waste pollution and composting technology, introduces the parameters that influence of the composting process and the optimal conditions, and presents the indicators for evaluating the decay of compost products and the evaluation criteria as well. In the composting process, small-molecule organic acids produced by the degradation of easily degradable organic matter such as sugars and lipids and various enzymes produced by microorganisms (phytase, phosphatase, etc.) can mineralize organic phosphorus such as phytate and phospholipids, promote phosphorus activation and provide phosphorus sources for microorganisms, so the conversion of organic matter and phosphorus is related to the fertilizer effect of composted products. Therefore, the clarification of the characteristics of organic matter and phosphorus transformation in the composting process is an important prerequisite for the resource utilization of agricultural organic waste. This paper provides theoretical support for the sustainable utilization of agricultural organic waste resources.

Titanium dioxide (TiO₂) nanostructures are well known for their excellency in photocatalytic activities. In this work, additive-free and Cd metal ion - incorporated titanium dioxide (TiO₂) nanoparticles have been prepared to employ a facile route of synthesis using a hydrothermal method. Metal-metal nanocomposites have been synthesized by incorporating cadmium (Cd) with the appropriate amount of TiO₂ nanoparticles. The properties of the derived materials had been investigated by employing various characteristic tools such as various techniques, including X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), UV–visible absorbance spectroscopy (UV–vis), and photoluminescence spectroscopy (PL) are all examples of advanced imaging techniques, that may be used to study materials. Using a method known as a vibrating sample magnetometer, we measured the magnetic properties of bare and Cd-doped TiO₂ nanoparticles. The investigations on crystalline nature of samples are agreed well with the standard crystalline features of TiO₂ nanoparticles. Emerged grain sizes have been estimated for all samples of pure and additive incorporated TiO₂ samples. Morphological characterization revealed that different particle features varied with the compositional changes. Spectral and optical absorption spectra of the prepared nanoparticles ensured the yield of derived TiO₂ nanoparticles with the additive component. An evaluation of the photocatalytic activity of Cd doped TiO₂ nanoparticles under UV irradiation was made using the methylene blue (MB) degradation method. The photodegradation efficiency were studied under visible light which confirms that the material is gifted one for water-treatment technologies to meet the rising clean water shortage.

Organic redox flow batteries have attracted a lot of interests both in academics and industries. Accordingly, many organic materials and chemistries have been studied, providing a solid foundation for development of low-cost organic flow batteries. However, capacity loss/fade as a result of organic molecule decomposition/degradation is a major hindrance towards further advancement of this promising, sustainable and large-scale energy storage technology. Understanding the causes of decomposition as well as its mechanism is thus necessary to unravel this major challenge. Therefore, this perspective/views focus on highlighting the different methods that can be employed for decomposition assessment of organic molecules in flow battery systems. This will help in engineering and designing stable electroactive organic molecule to enable development of durable and long cycle life redox flow battery.

The composite Ni-SDC cathode is a key element in the formulation of the hybrid MCFC/SOFC system. It must encompass electrical and ionic conductivity, high catalytic activity to allow for the reduction of oxygen and the oxidation of carbon dioxide and provide high permeability for gaseous reactants. This requires not only a specific chemical composition but also the microstructure has to be designed and specifically manufactured.

These studies present the thermal treatment process and resultant properties of Ni-SDC cathodes with various SDC volume fractions. A new procedure for producing the Ni-SDC cathode was optimized based on the reference sintering process for pure Ni, modifying the temperature profile as well as the atmospheric gas composition (air, nitrogen, nitrogen + hydrogen mixture) and the sintering temperature (800°C, 900°C, 1000°C). This was done using thermogravimetric analysis (TGA) and electron microscopy (SEM).

The research results show that the addition of SDC, with a specific atmospheric formulation, facilitates the organic phase decomposition. It has been observed that an increase in sintering temperature enhances mechanical strength and improves electrical conductivity.

The molecule-water and molecule–molecule interactions are the main keys to understanding the behavior of polysaccharides in an aqueous solution. In this work, electrical impedance spectroscopy is used to investigate raw polysaccharides' dielectric and electrical properties. Impedance data were carried out for different concentrations in the frequency range [10^-2–10⁶Hz] and then analyzed in Nyquist and bode representation, revealing one clear maximum due to the electrode polarization. Therefore, the complex conductivity is analyzed and makes the other relaxation processes very clear.

Moreover, an appropriate equivalent circuit was developed, showing good agreement with the experimental data. The extrapolation and deconvolution approaches in the frequency range [10^-3–10⁷Hz] were performed to confirm the presence of the three relaxation processes and the validity of the equivalent circuit. The first was attributed to the electrode polarization, and the other processes were attributed to the molecules-water and molecule-counterion interactions. Finally, a clear transition at 5% (w/v) is shown in the evolutions of the conductivity, suggesting the transition from the dilute to the semi-dilute domain.