Materials Science for Energy Technologies最新文献

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.

The synthesis of LaFe_1-xAl_xO₃ (x = 0–0.2) on the structure and electromagnetic properties using the co-precipitation method were evaluated. LaFe_1-xAl_xO₃ (x = 0–0.2) materials were synthesized using lanthanum chloride and natural iron sand powders. The mixing process of precursors was held with a hotplate temperature of 60 °C. The calcination process was done at 400 °C for 2 h. Then samples were analyzed using X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Vibrating Sample Magnetometer (VSM), and CV meter. The XRD patterns result in two phases of LaFeO₃ and Fe₂O₃. SEM images were performed that the powders are porous agglomerates. The particle size distribution is shown in the histogram that the samples are in the range of 50–500 nm, respectively. Then, the magnetic properties measurement of VSM analysis studied the substitution of Fe to Al ions decreases magnetic properties and BHmax in LaFe_1-xAl_xO₃ (x = 0–0.2). The I-V measurements conducted the substitution of Fe to Al ions increase with a nonlinear reversal current in LaFeO₃. These results show that LaFe_1-xAl_xO₃ (x = 0–0.2) was recommended as the magnetic permanent material and perovskite material based on electromagnetic properties.

One of the most significant industrial processes is the catalytic methanol synthesis from carbon dioxide because methanol is a future energy carrier for producing fuels and high-value-added commodities, the so-called “methanol economy” is carbon neutral. As a solution to climate change, the widespread belief that carbon dioxide can be recycled by hydrogenation into methanol has motivated the development of more efficient and selective catalysts. Efficient 2 wt% Pd/CeO₂ catalysts for thermochemical CO₂ hydrogenation have recently been investigated. However, the rationale behind the low Pd loading (2 wt%) in CeO₂ needs to be clarified, and comprehensive research into Pd tuning is lacking. In this article, we describe the synthesis ofvarious palladium contents (0.5, 1, 2, 4, and 6 wt%) supported on ceria nanorods (Pd/CeO₂) for selective hydrogenation of CO₂ to methanol under vapor-phase. The impact of Pd on the physicochemical properties of CeO₂ was examined using various characterization techniques. The enhanced catalytic activity was caused by the 2 wt% Pd/CeO₂ catalyst's most significant level of metallic Pd species, strong interactions between Pd and CeO₂, uniform Pd dispersion on CeO₂, increased reducibility, oxygen mobility, and weak basic sites. This study reveals that changing the percentage of metal in the catalyst supports a valuable technique for designing efficient oxides-supported metal-based catalysts for CO₂ conversions.