Materials Science for Energy Technologies最新文献

The experiment was carried out by growing BaTiO₃ (Undoped or Li-doped) on p-type Si_(1 0 0) substrates using the Chemical Solution Deposition (CSD) method and spin coating at a rotational speed of 3000 rpm for 60 s, followed by heating at 850 °C. The characterization results show that the bandgap energy value of the thin film due to lithium doping reduces the bandgap energy value. This is presumably because the donor atom added to a semiconductor causes the allowable energy level to be slightly below the conduction band. The presence of this new band causes the thin film bandgap energy to decrease with a five-valent tantalum dip. The morphological properties showed that the BaTiO₃/Si_(1 0 0) thin film particles in the deposited lithium had a fairly homogeneous grain. With the addition of lithium acetate as a binder into barium titanate, the grain size is getting smaller because it is suspected that the lithium-ion radius is smaller than the barium-ion radius. Measurement of I-V on the thin film shows that the output voltage value increases with more light intensity hitting the surface of the thin film. The greater the light intensity, the greater the energy of the photons, so the electrons are easier to jump. The three things above (both electrical and morphological properties) conclude that the thin films grown have the potential for photovoltaics.

Recent concerns regarding climate change and rising energy costs have dramatically increased interest in using alternative energies, especially biomass energy which is carbon neutral. Hemp is among the fastest-growing plants with unique fiber characteristics. The objective of this study was to investigate the physical and chemical properties of hemp stalks of seven different clones and to assess their feasibility as a sustainable bioenergy resource. Seven clones (KU03, KU18, KU27, KU45, KU49, RPF1, and RPF2) of four-month-old hemp (Cannabis sativa) were used in this work. Physical properties, volatile content, fixed carbon, ash content, calorific value, chemical composition, ash composition, and metal element of the samples were investigated. The results revealed that hemp stalk had desirable fuel characteristics with high volatile substance, high heating value, low ash content, very low nitrogen content, and non-detectable sulfur. Selecting well-adapted clones and appropriate technology which can convert the hemp stalks to suitable bioenergy forms are important aspects of bioresource management. Based on our findings, some selected hemp clone biomass possessed excellent characteristics and great potential to be used as raw material for bioenergy production.

Different polylactic acid (PLA) thin films containing clarithromycin and a number of metal oxide nanoparticles (magnesium, titanium, zinc, and nickel) dioxides were created. Low dosages of metal oxides (0.01% by weight) and clarithromycin (0.5% by weight) were used to make transparent films. The role of metal oxide nanoparticles and clarithromycin as UV blockers for PLA photodegradation was looked at. The durability of polymeric materials is improved more by clarithromycin in combination with metal oxides than by clarithromycin alone in PLA films. An analysis of the weight loss, surface morphology, and changes in infrared spectra of irradiated polymeric blends revealed that nickel oxide and clarithromycin together function as effective UV blockers and offer PLA a high degree of protection. Nickel oxide nanoparticles were the best addition for PLA stability. Highly alkaline metal oxides are present. Contrarily, the heteroatom and aromatic nature of clarithromycin enables it to absorb damaging radiation and function as an ultraviolet absorption. Thus, the adaptability of PLA to photodegradation was significantly improved by using a mixture of metal oxide nanoparticles and clarithromycin.

In this study, S and Bi Co-doped carbon quantum dots were synthesized and their application for Cd(II) removal was investigated. All the experiments were performed in batch mode and effect Bi/S ratio on pH was investigated. It was observed that 12 pH is most suitable for fast removal of Cd²⁺. The optimized Bi/S ratio was further investigated for effect of adsorbent dosage, initial concentration of Cd(II). Addition of four scavenger solvent namely formaldehyde, acetic acid, ethanediamine and methanol was investigated for enhancement in the photocatalytic activity. Maximum removal efficiency was observed with ethandiamine ∼94% at 300 ppm as compared to formaldehyde (∼90.3%), methanol (∼86.7%) and acetic acid(∼86.3%) indicating that amine group is more suitable as scavenger molecule. Adsorption isotherms of Cd(II) on Bi/S doped on CQD were fitted for different adsorption isotherm model namely Langmuir, Freundlich and Temkin isotherms. Both Lanmguir and Temkin isotherm were observed to fit well with R² value above 98% as compared to Freundlich with lower R² value (∼95.3%), indicating that a combination of chemisorption phenomenon as well as availability of energy of electron could be responsible for the Cd(II) removal. Thermodynamic parameters both enthalpy change and entropy change were estimated as −10.76 kJ/mol and −11.2 kJ/mol K. All three parameters were negative indicating that the process was spontaneous and exothermic.

The coating materials, thickness and number of layers directly influence the reflectance and absorptance properties of the thin films. However, while selecting the materials for single and coatings, the substrate’s refractive index; bond layer, functional layer and protective layer have to be carefully chosen to obtain the desired reflectance and absorptance values. Hence, modelling and simulating the thin film coatings is essential before conducting the experiments to get meaningful results. The simulation results of single coatings have been discussed. Generally, glass is one of the widely used substrate materials for solar reflectors, aluminum is the optimal functional material, with a reflection of 93 % of light. Nickel would be a preferable functional layer with a reflection of 64 % and absorptance of 36 %, Si₃N₄ being the acceptable bond layers and protective layers with a reflection of 68 % some solar thermal receiver tube applications however research effort is being made to find alternate lightweight materials for this application. Polycarbonate has been chosen as an alternate material for the substrate because it is light in weight with a reflection of 93 %, which is durable and not fragile.

Quantum dots play an important role in third-generation photovoltaics. The key focus on quantum dots is due to their cost effect, capacity to work in diffused light, ease of fabrication, light weight, and flexibility which pique curiosity to further research. The incorporation of quantum dots into photovoltaics results in theoretically high thermodynamic conversion efficiencies of up to 40%, but in practise, the efficiencies are lower than those of dye-sensitized solar cells. Recent developments of different components like photoanode, quantum dot sensitizer, electrolyte, and counter electrode were discussed in detail. It was observed that by changing the synthesis methods, the adhesion properties might vary, which leads to enhancing the photovoltaic properties such as power conversion efficiency (PCE), open circuit voltage (Voc), short circuit current (Jsc), and fill factor (FF). The first report on the efficiency of Quantum Dot Sensitized Solar Cells (QDSSCs) was 0.12%. As of today, the efficiency is reported as 18.1 %, and further, the researchers are working to improve the efficiency of QDSSCs.

Optimizing electrocatalytic activity and recognizing the most reactive sites for oxygen evolution reaction (OER) electrocatalysts are valuable to the order of renewable power. In this research article, we explored an innovative in-situ annealing technique for constructing iron carbide nanoparticles (Fe₃C NPs) encapsulated via nitrogen and phosphorous doped bamboo-shape carbon nanotubes (NP-CNTs) for OER. Interestingly, the constructed Fe₃C NPs@NP-CNT-800 composite exhibited remarkable electrochemical operation and offered a stable current density of 10 mA/cm² at a lower overpotential (280 mV) in an alkaline solution. Furthermore, an innovative Fe₃C NPs@N,P-CNT-800 hybrid surpassed the standard RuO₂ electrocatalyst in terms of OER performance and showed negligible degradation in chronoamperometric (21 h) and chronopotentiometry (3000 cycles) analyses. The remarkable performance and stability are ascribed to the Fe₃C NPs, novel tubular bamboo-like morphology of its carbon materials, and heteroatom doping, which contribute to the electrochemical interfaces, large surface area, active catalytic sites, and rapid charge transfer kinetics.

Research has been carried out on indicator electrodes (1) PVA-Enzyme/PVC-KTpClPB, sensitivity 19,069 mV/decade, detection range 1.10⁻⁵–5.10⁻⁴ M, detection limit 1.10–5 M. The width of the peak UV–vis absorbance is narrow (2) PVA-Enzyme/GA-2.9 %/PVC-KTpClPB wide UV–vis absorbance peak but the absorbance peak decreased, (3) PVA-Enzyme/GA-2.9 %/PVC-KTpClPB-o-NPOE XRD analysis amorphous spectral pattern appeared (4) PVA-Enzyme/GA-2.9 %/PPy + H₂SO₄/PVC-KTpClPB-o-NPOE (5) PVA-Enzyme/GA-2.9 %/PPy + Sulfonic Acid/PVC-KTpClPB-o-NPOE, amorphous spectrum pattern in (4) and (5) were greatly reduced for the enzyme variation of 0.6 g in 0.5 mL (50 % water + 50 % alcohol). GA plays a role in increasing the detection range, o-NPOE forms amorphous, enzyme variations increase the intensity of the XRD spectrum pattern. The method of developing a gradual modification of the indicator electrode membrane by cross-linking GA, o-NPOE, conductive polymer. The best results were obtained at the indicator electrode PVA-Enzyme/GA-2.9 %/PPy + Sulfonic Acid/PVC-KTpClPB-o-NPOE. Analysis of the linear curve of the sample EI₅-1 with a sensitivity of 41.56 mV/decade, a detection range of 10⁻⁴–10⁻¹ M and a detection limit of 10⁻⁴ M, R² = 97.51 %. The best indicator electrode is EI₅-1.