Materials for Renewable and Sustainable Energy最新文献

In this work, different varieties of dye sensitized solar cells are fabricated by simple fabrication process. In this fabrication extract of butea monosperma flower, methylene blue and methyl orange dyes are used as sensitizers. The photovoltaic performance of dye sensitized solar cells (DSSCs) has been studied. The performances of two different types of photo-electrodes are also tested in this work. The morphology and bandgap of TiO₂ (titanium dioxide) and ZnO (Zinc oxide) was observed from XRD, FTIR spectroscopy and UV-vis Spectrum. It is found that TiO₂ based DSSCs have better performance. It also observed that the current density and efficiency was increased from 7.46 to 12.9 mA/cm² and from 1.34 to 6.8% respectively when using methyl orange as a dye. Hence it can be said that methyl orange dye enhanced the photovoltaic performance of DSSC.

Herein, human hair-derived activated carbon (HH-AC) with remarkable physisorption properties such as high surface area and well-balanced micro- and mesopores, is synthesized by chemical activation method using potassium hydroxide (KOH). The activated carbon is synthesized at different ratio of charred human hair and activator as 1:1, 1:2 and 1:3 for HH AC(11), HH-AC(12) and HH-AC(13), respectively. These activated materials are characterized by a powder X-ray diffraction (XRD), Laser Raman spectroscopy, Scanning electron microscope (SEM), and (:{text{N}}_{2}) adsorption/desorption isotherms. To examine the influence of the micro-mesopore ratio with high surface area on supercapacitor behavior, all samples are tested in a three-electrode using 2.5 moles of potassium nitrate (2.5 M KNO₃) as electrolyte solution. The results show that HH-AC(12) sample which has micro to mesopore-balanced(:(50:50):) exhibited superior electrochemical performance with specific capacitance of (:215:text{F}:{text{g}}^{-1}) and (:125.8:text{F}:{text{g}}^{-1}) in the negative and positive potential, respectively at (:1:text{A}::{text{g}}^{-1}). The sample HH-AC(11), which is dominated by micropores, showed lower rate capability and specific capacitance despite the huge surface area.Whereas the HH-AC(13) sample with mostly mesopores achieved higher rate capability compared to the others. The HH-AC(12) is further examined in a 2-electrode setup to form a symmetric device. The results show a specific energy of (:16:text{W}text{h}:text{k}{text{g}}^{-1}) and a specific power of (:375:text{W}:text{k}{text{g}}^{-1}) at (:0.5:text{A}:{text{g}}^{-1}). The device demonstrates outstanding capacitance retention of (:97text{%}) after 10,000 cycles. Thus, ACs with micro to mesopores-balanced are potential candidates for supercapacitor applications.

Using of agricultural residues for briquette production attracts the attention of many researchers to overcome the problems related to the usage of fossil fuels as an energy source. This study focused on the production of briquettes from sesame stalks as an alternative fuel in Cement industries. The briquettes were produced from carbonized sesame stalks using paper waste, cow dung, and a mixture of cow dung and paper waste binders. The data analysis of the charcoal briquettes was carried out using two-way ANOVA without replication using Microsoft Excel. The binder ratio and binder types have a significant effect on the density and shatter resistance. Briquettes made using carbonized sesame stalks have the highest density of 1.133 g/cm³ at 5% of cow dung binder. The highest shatter resistance having a value of 91.00% was found in carbonized briquette prepared using 25% cow dung binder. Six briquettes were selected for proximate and calorific value analysis. The highest heating value of the produced briquettes was 4794.38 kcal/kg at 5% of cow dung binder, which has moisture, ash, fixed carbon, and volatile matter of 6.54, 14, 30.7, and 48.76% respectively. Carbon, hydrogen, oxygen, nitrogen, and sulfur contents of a briquette, which has the highest heating value, were recorded at 46.34, 2.50, 50.89, 0.27, and 0.00% respectively. Production of a briquette from carbonized sesame stalks using 5% cow dung binder is suitable from economic and environmental points of view.

The utilization of fossil fuels for power generation results in the production of a greater quantity of pollutants and greenhouse gases, which exerts detrimental impacts on the ecosystem. A range of solar energy technologies can be employed to address forthcoming energy demands, concurrently mitigating pollution and protecting the world from global threats. This study critically reviewed all four generations of photovoltaic (PV) solar cells, focusing on fundamental concepts, material used, performance, operational principles, and cooling systems, along with their respective advantages and disadvantages. The manuscript analyzes various materials, including their performance, physical properties (electronic and optical), biodegradability, availability, cost, temperature stability, degradation rate, and other parameters. The sensible engineering of effective solar devices made of cutting -edge materials along with nanostructured ternary metal sulphides, and three-dimensional graphene are also briefly discussed which are more versatile, stable, thin and light weight with high performance as compare to third generation solar cells. The impact of material alterations is delineated in PV, where the efficiency of solar cell technology has improved from 4% to 47.1%. Further the research article deals with different internal and external stress factors affecting the solar PV module performance.

TiO₂ has attracted a lot of attention as anode material for sodium-ion batteries due to its higher operating voltage, safely and low lost material, but TiO₂ has two main issues, low electronic conductivity and slow solid-state ion diffusion. These issues have been successfully resolved by researchers using carbon coating on TiO₂. In this work, carbon coated TiO₂ (CC-TiO₂₎ nanoparticles have been synthesized by using TiO₂ and sucrose as soluble source of carbon. The carbon coating on TiO₂ particles was formed after heat treatment in inert atmosphere. CC-TiO₂ particles exhibited reversible capacity of 116 mAh g^− 1 at 0.1 C after 50 cycles, and high capacity retention of 77% after 100 cycles in a sodium-ion battery cell. The impressive electrochemical performance of the TiO₂ particles is due to several factors: the small size of the crystallites, the continuous electronic network created by the close contact of individual carbon-coated TiO₂ particles, and the efficient penetration of the mesopores by the electrolyte.

Increasing the Te content in stoichiometric Bi_0.5Sb_1.5Te₃ facilitates effective control over the anti-site defects and nanostructure; however, arresting excess Te in the host matrix is challenging. Herein, we report the success of a saturation-annealing treatment in a vacuum, followed by air-quenching as a promising approach for synthesizing high figure-of-merit (zT) Bi_0.5Sb_1.5Te₃+xTe (x = 0, 2, 5 and 10 wt%) materials. A remarkably high-power factor (α²σ ~ 6 mW at 300 K) is achieved in p-type Bi_0.5Sb_1.5Te₃ + 5 wt% Te composition due to high carrier concentration (n) and good carrier mobility (µ). Microstructural analysis revealed the formation of densely interconnected polycrystalline grains featuring fine grain boundaries, planar/point defects, and strain field domains, contributing towards wide-length scale phonon scattering. The cumulative effect of drastically reduced thermal conductivity (κ ~ 0.8 W/m-K at 300 K), and enhanced power factor resulted in a record zT value ~ 2.2 at 300 K in Bi_0.5Sb_1.5Te₃ + 5 wt% Te, with an average zT value up to 1.35 in temperatures ranging from 303 to 573 K. The COMSOL simulations predict a maximum conversion efficiency (η_max) of ~ 15%, at a temperature gradient (∆T) of 270 K, for a single-leg thermoelectric generator (TEG) developed using this material.

In the pursuit of higher conversion efficiency, the PV industry has turned its focus towards perovskite-silicon tandem solar cells, which currently represent the peak of innovation. To surpass the efficiency limits of traditional single-junction cells, researchers are exploring the potential of these tandem solar cells by integrating the merits of perovskite and silicon. However, integrating these cells brings different challenges, such as deposition methods and material misalignments. Thus, in this work, we are using advanced simulation techniques, including Silvaco ATLAS’s Victory Process and Device Simulator to imitate the actual manufacturing processes. Primarily this research work focuses on three scenarios: shunting, planarization and conformal deposition to emulate the experimental conditions. The obtained results show the potential and effectiveness of process simulations in accurately predicting and improving the PV performance of the tandem solar cell. Two different perovskite-silicon tandem solar cells are designed using process simulations which showed a conversion efficiency of 27.51% and 29.08% respectively. This work highlights the importance of using simulation tools for the further development of tandem solar cell technology. Detailed process and device simulations reported in this work may pave the way in the fabrication of optimised perovskite/silicon tandem solar cell.

This research reveals the application of electrochemical impedance spectroscopy (EIS) in analyzing and improving the performance of hydrogenated amorphous silicon (a-Si: H) based photovoltaic cells. As a non-destructive technique, EIS provides deep insight into the electrochemical characteristics of photovoltaic cells, including series resistance, layer capacitance, recombination mechanisms, and charge transport. The impedance data is obtained and analyzed using small AC potential signals at various frequencies via Nyquist diagrams and Bode plots. This analysis allows the identification of resistive and capacitive elements as well as the evaluation of the quality of the interface between the active layer and the electrode. The results show that EIS can identify internal barriers that reduce the efficiency of a-Si: H solar cells, such as dominant recombination mechanisms and inefficient charge transport. Using equivalent circuit models, electrochemical parameters are extracted to reveal cell behavior and performance. In addition, these results also confirm that EIS is an important tool in design optimization and performance improvement of a-Si: H photovoltaic cells, providing a solid scientific basis for the development of more efficient and sustainable solar cell technology. These findings contribute to efforts to increase solar energy efficiency, supporting broader and more effective use of photovoltaic technology in meeting global sustainable energy needs.

In this study, aluminum-based wastes are used as energy carriers for on-demand hydrogen production through sustainable, eco-friendly, and cost-effective controlled electrochemical corrosion in aqueous solution. The electrochemical process is very effective because it (i) uses waste metals to produce hydrogen, (ii) corroborates to circular economy, (iii) produces high purity hydrogen, (iv) is based on simple hydrolysis reaction of metals in relevant solutions, (v) electricity is not required and (iv) recovers part of the chemical Gibbs energy of the electrochemical corrosion usually entirely lost in the environment. We systematically studied the generation of hydrogen from industrial waste Dust Scrap Aluminum Alloy (DSAA) belonging to Al 6063 series for the first time. The process is investigated in a novel hand-made batch reactor with a low-cost commercial body suitable to an easy scale-up. Kinetics of DSAA hydrolysis reaction was explored by measuring the variation of aluminium ion concentration at different immersion times through Inductively Coupled Plasma (ICP) and weight loss measurements at different temperatures and NaOH catalyst concentrations. The effect of hydrolysis reaction on the composition and morphology of the metal surfaces in terms of formed oxide layers was studied in detail using Optical Polarizing Microscopy (OPM), Energy dispersive X-ray (EDX) and Scanning Electron Microscopy (SEM) techniques. The criteria used to evaluate the hydrogen reactor performance were hydrogen (i) yield and (ii) production rate. The experimental results showed that a strong increase in NaOH concentration (from 0.75 to 5 M) corresponding to a slow increase in hydrolysis reaction temperature (from 38.8 to 49.9 °C) lead to an improvement in hydrogen generation rate of one order of magnitude, i.e. from 35.71 to 421.41 ml/(g∙min). Low but constant rate of hydrogen can be generated for longer times at low NaOH concentrations (0.75 M), while fast and variable hydrogen generation rate occurs at higher concentrations (5 M) in short times. In the case study of Al 6063 series waste scrap, the hydrolysis reactor parameters can be regulated to deliver hydrogen generation rates from 35.71 to 421.41 ml/(g min) according to requirements. We expect that the results presented in this work will encourage researchers to study the possible use of other metal-based and multi-material plastic/metal wastes thermodynamically prone to electrochemical corrosion process as possible source of hydrogen.

Graphical Abstract

This study introduces a high-performance electrode coated with MnO_x compounds to enhance the HER reaction. The active and precipitated MnO_x species facilitate interconnected electron transport throughout the Ti electrodes. The tailored MnO_x electrodes exhibited a significant reduction in R_ct (69.7%), superior C_dl (31.6%), and a notably lower Nyquist ring compared to traditional Ti electrodes, confirming their excellent electrocatalytic performance in Cl⁻ and NaCl production. Additionally, LSV and PDP analysis demonstrated that the MnO_x electrodes achieved a 53.9% decrease in Tafel slopes (from 139 mV/decade to 64 mV/decade), lower activity potentials, and robust corrosion resistance (99.4%), indicating faster kinetics and higher efficiency. High-resolution FESEM and contact angle images revealed that the MnO_x electrodes possess uniform porous networks and semi-super hydrophilic function, optimizing H₂ release and expanding the interfacial area for electron transfer. Finally, the Ti electrodes with advanced MnO_x coatings can serve as reliable, cost-effective, and efficient candidates for use as regenerating electrodes in electrocatalytic industries. Moreover, the novel MnO_x/rGO composites are versatile materials used as catalysts in chemical reactions, effective electrodes in energy storage devices, sensitive gas sensors, and for water treatment to remove contaminants.