Abstract: A two-step electrodeposition approach was applied to deposit Sn/C layers on a Ni foam substrate. The first step was the deposition of the Sn layer using two electrodeposition modes (direct and pulsed electrodeposition) with different parameters (duty cycle, time on/off, and effective time). The second step was to deposit carbon on the Sn layer by direct electrodeposition. The surface morphology, chemical composition, and phases of deposited layers were investigated and the electrochemical behavior of Sn/Ni and C/Sn/Ni anodes was characterized. The pulsed electrodeposition technique with a lower duty cycle (15% duty cycle with time ratio ton/off = 3/17 for 2 min) produced more uniform and compacted deposits, compared to the non-uniform and dendritic morphology obtained after high duty cycles (50%) as well as direct electrodeposition. After the direct electrodeposition of carbon on the pulsed electrodeposited Sn, a uniform layer containing ~ 10% C, 38% Sn, 45% Ni, and 7% O, was detected. Analysis of this layer confirmed the presence of Ni, Sn, and amorphous C. Electrochemical characterization showed that the C/Sn/Ni anodes with a 94 Ω polarization resistance, a 0.105 V/decade anodic Tafel slope and 0.202 V/decade cathodic Tafel slope manifested the highest apparent and intrinsic catalytic activities. The peak current for the C/Sn/Ni samples was higher than the peak current for the Sn/Ni samples at all scan rates, indicating higher electrochemical reactivity. The linear relationship between the peak current and the scan rate's square root suggests that diffusion controls the charge transfer process. PubDate: 2025-04-17
Abstract: Solar energy harvesting and conversion has attracted a lot of scientific interest because solar energy is believed to be clean and sustainable. In this study, we report the synthesis of porous TiO2 by sol-gel method and later doped with Thulium rare earth ions (Tm3+) for potential application in organic solar cells as electron transport layers (ETL). Additionally, density functional theory (DFT) calculation was performed with CASTEP computational suite to explore further the optoelectronic and charge transfer mechanisms in the Tm(III)-doped TiO2 nanomaterials. Thereafter, the experimental material’s band gap values were extracted and used in the numerical simulation of the designed organic solar cell with a general configuration of FTO/TiO2/PBDB-T/ITIC/Cu2O/Ag, via SCAPS-1D numerical simulator. The experimental results showed a steady reduction in the band gap of TiO2 with increased Tm3+ doping. The electrical conductivity properties showed an enhanced feature when TiO2 was doped with Tm3+ nanoparticles. The calculated band gap from the density functional theory study shows a similar decreasing band gap trend with that of the experimental data, suggesting the transport properties from DFT are sufficient to describe the experimental data. The electronic transfer behaviour is analogous to metal-metal and metal-oxides transport features, which can be attributed to Ti – Tm and Tm – O – Ti hybridizations, as indicated in the orbital state alignment. The best performing modelled device with Tm(III)-doped TiO2 (1.0 mol%) as ETL attained a PCE of 21.83%, Voc of 1.54 V, Jsc of 31.87 mA cm− 2 and FF of 44.44% which was attributed to better charge transfer characteristics and effective band alignment between the ETL and absorber, thus, better efficiency. The study proposes that Tm(III)-doped TiO2 can act as a suitable n-type material that can propel the realisation of high-performance OSCs for commercialization in the future. PubDate: 2025-03-28
Abstract: This work improved energy efficiency, stability and energy stability in organic and organic perovskite solar cells, by using titanium dioxide as anti-reflective coating on silver. The use of graphene oxide-nickel oxide layer as a hole-transporting layer enhanced carrier mobility in addition to incrementing stability. The outcomes that have been meticulously extracted and analyzed from the finite-difference time-domain (FDTD) simulations provide compelling evidence that this particular methodology can be adeptly utilized to significantly enhance the capability to attain a remarkably broad absorption spectrum across a wide range of wavelengths, specifically those identified frorm 200 nm to 900 nm, which are of critical importance in solar cell applications. Optical analysis was conducted by Maxwell method. Dielectric plasmonic wire grating was proposed to increase optical absorbance and achieve maximum current. The electrical analysis of the structure was based on Poisson’s equations. Optical analysis of the inorganic halide perovskite revealed current density, open circuit voltage, fill factor, and power of 34.294 mA/cm2, 1.04 V, 0.83369817, and 1.64 mA/cm2. The energy conversion efficiency was also 29.3%. PubDate: 2025-03-07
Abstract: Non-fullerene acceptors are promising materials for organic solar cells because of their flexibility and low cost; however, their long-term stability remains a critical challenge. In this study, we investigate the degradation mechanisms of conventionally structured solar cells (ITO/PEDOT: PSS/PM6/Y7/PDINO/Ag) under different environmental conditions: nitrogen preservation, encapsulation, and air exposure. Using the metal-insulator-metal (MIM) model, we simulate the current-voltage characteristics and extract key parameters to understand the physical mechanisms governing device degradation. The results show that air exposure primarily affects the anode interface, reducing the interfacial dipole energy and shifting the Fermi-level alignment of PEDOT: PSS, which is crucial for efficient hole extraction. This process leads to a deterioration in the hole transport properties over time, significantly affecting device performance. In contrast, the cathodic interface remains stable, suggesting that degradation is largely driven by changes in the hole transport layer. These findings provide critical insights into the interfacial degradation mechanisms of the NFA-based solar cells. Understanding these effects will aid in the development of strategies to enhance the stability and efficiency of organic photovoltaic devices for long-term operation. PubDate: 2025-03-05
Abstract: Granular materials like sand have gained importance in thermal storage applications due to their stability and cost-effectiveness. However, excessive usage of sand can pose environmental issues. This study investigates recycled construction materials such as glass, asphalt, ceramic, and concrete as alternatives to natural sand for low-temperature TES applications. The materials were processed to similar grain sizes and evaluated for their chemical, thermophysical, and thermal storage properties through a six-hour charging cycle at 60 °C. XRF analysis revealed significant compositions, including high oxygen and silicon content in concrete and sand, respectively. Results indicate that sand with 0.189 W/m K recorded the highest thermal conductivity compared with concrete 0.172 W/m K, glass 0.131 W/m K, ceramic 0.159 W/m K and asphalt 0.159 W/m K. A higher specific heat capacity was observed in concrete at 755 J/kg K, followed by asphalt at 732 J/kg K, glass at 708 J/kg K, and sand at 688 J/kg K. However, ceramic is categorized for a lower specific heat capacity of 682 J/kg K. Absolute density evaluation indicates that sand is the densest material with 2662 kg/m3, contrary to concrete 2480 kg/m3, glass 2421 kg/m3, ceramic 2285 kg/m3, and asphalt 2436 kg/m3. More to the point, the Ragone plot for specific power and energy highlighted that ceramic has a rapid energy release and concrete demonstrated sustained energy storage capabilities. Volumetric power and energy density assessments indicated sand's outstanding performance. However, concrete registered a superior thermal storage among recycled materials. The results highlight that recycled materials, specifically concrete can be used for thermal storage applications like water heating in poor communities. PubDate: 2025-03-04
Abstract: 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. PubDate: 2025-02-25
Abstract: 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 $$\:97\text{\%}$$ after 10,000 cycles. Thus, ACs with micro to mesopores-balanced are potential candidates for supercapacitor applications. PubDate: 2025-02-25
Abstract: 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. PubDate: 2025-02-25
Abstract: 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. PubDate: 2025-02-19
Abstract: 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. PubDate: 2025-02-11
Abstract: Increasing the Te content in stoichiometric Bi0.5Sb1.5Te3 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) Bi0.5Sb1.5Te3+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 Bi0.5Sb1.5Te3 + 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 Bi0.5Sb1.5Te3 + 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 (ηmax) of ~ 15%, at a temperature gradient (∆T) of 270 K, for a single-leg thermoelectric generator (TEG) developed using this material. PubDate: 2025-02-06
Abstract: 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. PubDate: 2025-02-04
Abstract: 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. PubDate: 2025-02-01
Abstract: 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 PubDate: 2025-01-25
Abstract: In this work, a triple-junction tandem solar cell (TSC) has been designed in order to increase the photovoltaic (PV) performance through utilizing maximum light photons. To create three junctions in this work three subcells have been designed and optimized at its best PV performance. The optimization of all the three subcells have been done through the various variations in the absorber layer like thickness and bulk defect density (BDD). It has been seen that best PV parameters in the top middle and bottom cell are maximum at high thickness and low BDD. For the designing of triple junction tandem configuration, two filtered spectrums (FS1 and FS2) have been calculated for the proper current matching in the three subcells. The optimized triple-junction TSC demonstrates significantly enhanced PV parameters, including high open-circuit voltage (VOC- 2.750), short-circuit current density (JSC- 16.45 mA/cm2), fill factor (FF- 83.40%), and power conversion efficiency (PCE- 37.74%). The strategy of using filtered spectrums and exact design optimization provides a potential road to the next generation of high-efficiency tandem solar cells, furthering the field of renewable energy solutions. PubDate: 2025-01-21
Abstract: The existing energy-wastewater nexus may be resolved using metal oxide semiconductor photocatalysts in photocatalytic hydrogen production and pollutant degradation, which is a clean and sustainable process. SnO2 is one such well-researched and proven photocatalyst that is now in use, although it only works with ultraviolet light, which only makes up 4% of the total solar energy received. The present research aims to use iron as a dopant to make SnO2 active under visible light, enhancing reactions like water splitting and dye degradation. The sol-gel method was used to synthesize the photocatalysts. XRD, BET, UV diffuse reflectance spectra, PL spectra, XPS, and SEM micrographs were used to characterize the synthesized photocatalysts. For 7.5 wt% Fe-doped SnO2, a remarkable hydrogen generation rate of 18.81 µmol/hr under sunlight was achieved, nearly three times that of pure SnO2 (5.71 µmol/h). The nanocomposites display excellent photoreactivity towards RhB dye degradation with an optimal concentration of 7.5 wt% Fe-doped SnO2. This optimal composite photocatalyst removes 93% of RhB dye on 0.1 g/L photocatalysts in only 60 min under sunlight. Pristine SnO2 removes 36% of the dye under similar reaction conditions. The photoluminescence spectra of Fe-doped SnO2 had lower peak locations than the pristine SnO2, indicating a decreased rate of charge recombination and increased life duration of the active species. As a result, hydrogen generation rates and dye degradation efficiencies have increased significantly. The photocatalyst’s recyclability study revealed that the photocatalysts can be used efficiently for four cycles without significant reduction in the yield. PubDate: 2025-01-21
Abstract: The noticeable growth in the power conversion efficiency of solution-processed organo-inorganic halide perovskite solar cells (OIHPSCs) incited the photovoltaic community to look for limitations that hurdle the commercialization process. The surface and interface defects between the perovskite and electron transport layers are among the main challenges that cause significant non-radiative recombination losses, thereby they result in poor performance and stability. In this work, tetracyanoquinodimethane (TCNQ), a strong electron acceptor molecule, is applied at the interface between the photoactive perovskite and [6,6]-phenyl C61 butyric acid methyl ester (PCBM) layers to modify the interface, and enhance device performance and stability. Steady-state and time-resolved photoluminescence measurements were used to characterize the role of the TCNQ passivation in reducing non-radiative recombination of charge carriers. Current density versus voltage (J-V) measurements show improvement in devices open-circuit voltage (Voc), short-circuit current density (Jsc), and fill factor (FF) for devices with TCNQ interface passivation, which is attributed to suppressed non-radiative recombination. In addition, a noticeable improvement in the device’s stability was observed. This study reveals the dual role of TCNQ passivation in improving the photoelectric properties and stability of ambient air processed perovskite devices with the pin architecture. PubDate: 2025-01-21
Abstract: Typically, the methods for converting methane can be categorized into two primary groups: direct and indirect. Among these, the direct non-oxidative conversion of methane to higher hydrocarbons has received a lot of interest in recent years due to its distinct advantages over the indirect routes. Several catalysts based on transitional metals such as Ni, Fe, Co, Mo, etc. have been reported for the methane conversion, employing different supports. This study focuses on the direct non-oxidative decomposition of methane using monometallic catalysts based on silica. The catalysts, specifically Co, Ni, and Mo, were impregnated to the pre-synthesized silica support. The synthesized catalysts were characterized for crystallite size, surface area, morphology and thermal stability using X-ray diffraction, porosimeter, scanning electron microscope and thermogravimetric analysis, respectively. The effect of reaction temperature, amount of catalyst, methane preheating, flow rate of methane and presence of promotors on the decomposition reaction was investigated. PubDate: 2025-01-21
Abstract: This study introduces a high-performance electrode coated with MnOx compounds to enhance the HER reaction. The active and precipitated MnOx species facilitate interconnected electron transport throughout the Ti electrodes. The tailored MnOx electrodes exhibited a significant reduction in Rct (69.7%), superior Cdl (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 MnOx 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 MnOx 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 MnOx coatings can serve as reliable, cost-effective, and efficient candidates for use as regenerating electrodes in electrocatalytic industries. Moreover, the novel MnOx/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. PubDate: 2025-01-21
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