Abstract: Abstract Dye-sensitized solar cells (DSSCs) are low-cost solar energy conversion devices with variable color and transparency advantages. DSSCs' potential power efficiency output, even in diffuse light conditions with consistent performance, allows them to be used in building-integrated photovoltaics (BIPV) window applications. Significantly, the development of bifacial DSSCs is getting significant scientific consideration. Triiodide/iodide (I3–/I–) redox couple-mediated DSSCs require highly effective and stable electrocatalysts for I3− reduction to overcome their performance constraints. However, the commonly employed platinum (Pt) cathodes have restrictions on high price and unfavorable durability. Here, we report platinum nanoparticles (Pt NPs) incorporated into multiwalled carbon nanotubes (MWCNT) composites with lower Pt content as an efficient bifacial counter electrode (CE) material for DSSC applications. Pt NPs were homogenously decorated over the MWCNT surfaces using a simple polyol method at relatively low temperatures. CEs fabricated using Pt/MWCNT composites exhibited excellent transparency and power conversion efficiencies (PCE) of 6.92% and 6.09% for front and rear illumination. The results are expected to bring significant advances in bifacial DSSCs for real-world window applications. PubDate: 2023-11-28
Abstract: Abstract Renewable energy research has received tremendous attention in recent years in a quest to circumvent the current global energy crisis. This study carefully selected and simulated the copper indium sulfur ternary compound semiconductor material with cadmium sulfide owing to their advantage in photovoltaic applications. Despite the potential of the materials in photovoltaic devices, the causes of degradation in the photovoltaic efficiency using such compound semiconductor materials have not really been investigated. However, electrical parameters of the materials such as open circuit voltage, short circuit current density, and fill factor have been extensively studied and reported as major causes of degradation in materials’ efficiency. Furthermore, identifying such electrical characteristics as a primary degradation mechanism in solar cells, this study work is an ardent effort that investigates the materials' electrical behavior as a cure to the degradation associated with compound semiconductor-based photovoltaic. In this study, we numerically characterized the electrical properties such as fill factor, open circuit voltage, short circuit current density, power conversion efficiency, net recombination rate, net generation rate, generation current density, recombination current density, hole current density, electrons current density, energy band diagram, capacitance–voltage, electric field strength of the heterostructured CIS/CdS compound semiconductor material using SCAP-1D. We also investigated the effect of temperature on the electrical properties of heterostructured materials. The obtained results reveal the uniformity of the total current density in the material despite the exponential decrease in the electron current density and the exponential increase in hole current density. The extracted solar cell parameters of the heterostructured CIS/CdS at 300 K are 18.6% for PCE, 64.8% for FF, 0.898 V for Voc, and 32 mA cm−2 for Jsc. After the investigation of the effect of temperature on the CIS/CdS compound semiconductor material, it was observed that the solar cell was most efficient at 300 K. The energy band gap of the CIS/CdS compound semiconductor material shrinks with an increase in temperature. The highest net recombination rate and recombination current is at 400 K, while the net generation rate and generation current density are independent of temperature. The study, on the other hand, gave insights into the potential degradation process, and utilizing the study’s findings could provide photovoltaic degradation remediation. PubDate: 2023-11-25
Abstract: Abstract Methanolysis of yellow grease (YG) was performed to synthesize its corresponding methyl ester (YGME) using BaO loaded on ZSM-5 (BaO/ZSM-5) as a heterogeneous base catalyst that was prepared via metallic solution hydrolysis method and characterized using N2 adsorption–desorption (BET), surface basicity, XRD, TGA/DTA, SEM, FTIR and Raman techniques.### The Taguchi design approach was utilized to optimize the transesterification process factors, and among the parameters studied, calcination temperature was found to have a significant influence on YGME yield. At 70 ℃ for 3 h, a YGME yield of 95.9 \(\pm 0.94\) % was obtained using a methanol/YG molar ratio of 15:1 and 1 g (2 wt.% of YG used) of BaO/ZSM-5 sample calcined at 700 ℃. The BaO/ZSM-5 catalyst was reused six times with only a 15% decrease in activity. PubDate: 2023-11-24
Abstract: Abstract Degradation performance of photovoltaic modules (SPV) by real conditions has become increasingly problematic. In dusty areas, dust accumulation is one of the main concerns that may cause a significant determination of SPV efficiency. In the current study, the effect of four dust-accumulated densities of 6, 12, 18, and 24 g/m2 have been investigated in outdoor conditions in Cairo, Egypt. The performance evaluation of SPV modules in the form of front and backside temperatures of the SPV module has been evaluated in addition to current, voltage, power, and efficiency of the SPV modules. The results showed that, as compared with a clean SPV module, with increasing dust density from 6 to 24 g/m2 the frontside temperature of SPV modules were lower by 6–8 ℃. While their backside temperatures were found to be higher by 2–6 ℃. In addition, the difference between the backside and frontside temperatures of the SPV module ranged from 5 to 14 ℃ for dust modules as compared with 3 ℃ for the clean SPV module. The output power and efficiency of dusty SPV modules were found to be lower by 6–45% and 13–38%, respectively as compared with clean SPV module. The results clearly showed the importance of properly maintaining and servicing the SPV modules to avoid their degradation by dust accumulated. PubDate: 2023-11-23
Abstract: Abstract Dye-sensitized solar cells (DSSCs) rely heavily on the counter electrode for their performance, which is responsible for collecting and transferring electrons generated at the photoanode. While platinum (Pt) has traditionally been used as a counter-electrode material, its cost, limited availability, and environmental concerns make it an unsuitable option for large-scale implementation. Iron–nitrogen––carbon (Fe–N–C) catalysts are receiving increasing attention due to their high catalytic activity and low cost. This study aims to investigate the performance of Fe–N–C materials as counter electrodes in DSSCs and assess their potential as a sustainable alternative to currently used platinum. Two different Fe–N–C-based materials have been synthesized using different carbon and nitrogen sources, and their electrochemical behavior has been assessed using current–voltage curves and impedance spectroscopy. The catalyst comprised a higher amount of iron and nitrogen shows higher efficiency and lower charge-transfer resistance due to improved iodide reaction kinetics and proper stability under potential cycling. However, this catalyst shows lower stability under a passive ageing procedure, which requires further clarification. Results provide new insights into the performance of Fe–N–C-based materials in DSSCs and aid in the further development of this promising technology. PubDate: 2023-11-17
Abstract: Abstract Future revolution in photovoltaics will be hinged mainly on cost, health implication, and material stability and performance. Based on these criteria, lead-based inorganic photovoltaics, organic–inorganic hybrid, and silicon photovoltaics are screened-out. According to the literature, the lead-free inorganic perovskite solar cell is favorably disposed to cost and safe-health. However, the simultaneous solution to material stability, high defect density, and low power conversion efficiency (PCE) still remains a mystery that has not been solved. This research proposed the green-based modifiable CaZnBr4 as a potential candidate for lead-free solar cell application based on the principle of A-site cation with green-based additive incorporation. The green-based additive was obtained from Kola Nitida, Carica Papaya, Ficus Exasperata, and Musa paradisiaca. The elemental characterization of the green-based additives was performed using X-ray fluorescence spectroscopy (XRF). The optical, crystalline, and electronic properties were characterized using ultraviolet–visible (UV–Vis) spectroscopy, X-ray diffractometry, Quantum Espresso, scanning electron microscopy and SCAPS-1D. The green-base-modified CaZnBr4 showed significant PCE improvement by 3% with significant film and crystallinity formation. The stressed state of the parent compound CaZnBr4 shows that it may be better suited for thermovoltaics application. It is recommended that better results could be obtained when different synthetic routes and green-based additives are used to initiate the defect passivation protocols. PubDate: 2023-11-17
Abstract: Abstract Utilizing artificial intelligent based algorithms in solving engineering problems is widely spread nowadays. Herein, this study provides a comprehensive and insightful analysis of the application of machine learning (ML) models to complex datasets in the field of solar cell power conversion efficiency (PCE). Mainly, perovskite solar cells generate three datasets, varying dataset size and complexity. Various popular regression models and hyperparameter tuning techniques are studied to guide researchers and practitioners looking to leverage machine learning methods for their data-driven projects. Specifically, four ML models were investigated; random forest (RF), gradient boosting (GBR), K-nearest neighbors (KNN), and linear regression (LR), while monitoring the ML model accuracy, complexity, computational cost, and time as evaluating parameters. Inputs' importance and contribution were examined for the three datasets, recording a dominating effect for the electron transport layer's (ETL) doping as the main controlling parameter in tuning the cell's overall PCE. For the first dataset, ETL doping recorded 93.6%, as the main contributor to the cell PCE, reducing to 79.0% in the third dataset. PubDate: 2023-09-25
Abstract: Abstract In this study, we synthesized neat and loaded lead phosphate glass (PbO–P2O5) with the inclusion of Cr, Co, Ni, and Zn using an inexpensive sol–gel technique. These composites were then deposited on silica glass substrates. Our objective was to investigate the influence of these fillers on the properties of the glass. The concentrations of the fillers were varied from 0 to 16 wt%, and the resulting thin films were characterized by measuring the absorption coefficient and estimating the optical band gap at room temperature. Additionally, we measured the electrical resistivity of the semiconducting thin films as a function of filler concentrations and temperature. To assess the overall performance of the films, we calculated the figure of merit using the Iles and Soclof approach, considering the DC resistance versus free carrier concentration and absorption coefficient. Interestingly, our results revealed a significant improvement in the figure of merit at specific filler concentrations. The obtained results are comprehensive and provide detailed insights. They indicate that the thin films produced in this study have the potential to be useful in energy devices, particularly in applications involving P–N junctions and similar structures. PubDate: 2023-09-02
Abstract: Abstract The synthesis of δ-MnO2, δ-MnO2 carbon dots nanocomposite, and Fe/Cu-doped δ-MnO2 carbon dots nanocomposite has been successfully carried out through a stirring process at room temperature and 80 °C. The synthesized powder shows a low crystallization determined through XRD and TEM analysis. Furthermore, the carbon dots are well attached to MnO2 performing a core–shell composite material, while the doping ions Fe and Cu were incorporated into the matrix substitute Mn in the MnO6 octahedron, although potassium ions were also detected. The manganese possess an oxidation state of + 3 and + 4, which promotes the oxygen vacancy creation \({V}_{\mathrm{O}}^{\cdot\cdot}\) denoting the conductivity decrease. PubDate: 2023-08-04
Abstract: Abstract This work created, characterized, and used a magnetic biochar catalyst that is both eco-friendly and very effective. Sugarcane bagasse was selected as primary raw material for catalyst preparation, because it is renewable and ecofriendly biomass. Catalyst created by doping sugarcane bagasse biochar with magnetic material in the form of (FeSO4·7H2O). Thermogravimetric Analysis (TGA) and Fourier Transform Infrared spectroscopy (FTIR) were used to characterize the catalyst. In addition, physical and textural characteristics of the catalyst were identified and interpreted. The characterization outcome showed that the catalyst has good catalytic qualities. For the manufacturing of biodiesel, discarded cooking oil served as the primary feedstock. The experiment was created utilizing the Box–Behnken Design (BBD) technique. There are four variables with the following three levels each: temperature, methanol to oil ratio, catalyst concentration, and reaction time. 29 experiments in total were carried out. Using the RSM function, optimization was done. The optimal conditions for obtaining biodiesel yield—temperature, methanol to oil ratio, reaction time, and catalyst weight—were 43.597 °C, 9.975 mol/L, 49.945 min, and 1.758 wt%. A study of the produced biodiesel using a FTIR showed that the conventional biodiesel IR spectra were confirmed. All physiochemical characteristics found suggested the biodiesel complied with ASTM and EN norms. Overall, the synthesized catalyst had conducted simultaneous reactions in a single batch reactor and had demonstrated suitability for converting used cooking oil to biodiesel. PubDate: 2023-07-06
Abstract: Abstract Bio-based materials represent a promising alternative in building envelope applications, with the aim of improving in-use energy efficiency. They have the advantage of being renewable, low embodied energy and CO2 neutral or negative. In addition, they are excellent thermal regulators. This paper presents an overview of the state-of-the-art of bio-based materials used in building construction and their applications. The materials outlined include hemp, wood, date palm wood, cork, alfa and straw. Through this literature study we want to get a broad overview of the current state of theoretical and experimental studies of their hygrothermal characteristics and their thermal and energy performances. The aim is not to be exhaustive but to summarise the most important research results on these materials. This is the first part of a research work that deals with the contribution to the development of a new bio-based construction material to be used in building. PubDate: 2023-05-10
Abstract: Abstract Electrochemical reduction of CO2 is an effective method for storing intermittent renewable energy. This could result in fuel additives and chemical feedstocks such as alcohols. A challenge of electrochemical alcohol production is the transfer of electrons and protons, as well as the formation of C–C bonds. As of now, copper-based materials are the most commonly used and effective catalysts. Although CuOx is considered a promising catalyst for electrochemical CO2 reduction reactions (CO2RR), significant improvements in product selectivity are still needed. This paper presents some results obtained using copper oxide as a cathode, combined with 33% of ionomer, nickel iron as anode, and membrane Fumatech as electrolyte. As a result of physico-chemical experiments, morphological measurements of the cathode, electrochemical experiments carried out with a complete zero-gap cell operating under alkaline conditions, and gas-chromatographic (GC) analyses of the cathode outlet stream, we determined that methyl formate, ethanol, and propanol were mainly obtained at a rate of 116.3 μmol \({\text{g}}_{\text{cat}}^{-1} \, {\text{h}}^{-{1}}\) during operation at 2.2 V. PubDate: 2023-05-10
Abstract: Abstract In this work, we report that hydrogen (H2) doped in n-type a-Si:H thin films strongly influences the electronic correlation in increasing the conversion output power of solar cells. Type n a-Si:H thin films were grown using PECVD on ITO substrates with various H2-doping, to obtain various thin films for solar-cell applications. N-type a-Si:H thin films were prepared, and then characterized using ellipsometric spectroscopy, atomic force microscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy. The addition of doped-H2 to the thin layer shows a decrease in optical conductivity, while the energy gap in the thin layer shows a significant increase in the a-Si:H-type thin layer. Our results show that H2 doping plays a very important role in the electronic structure, which is indicated by the significant energy gap difference. On the other hand, the bond structure of each H2-doped thin film showed a change from amorphous to nanocrystalline structures which were evenly distributed in each H2-doped bonding. Overall, we believe that the addition of doped-H2 to our findings could help increase the power conversion output of the solar cell due to the modification of the electronic structure. PubDate: 2023-04-12
Abstract: Abstract Bioenergy is one of several renewable energy options derived from biomass that can help satisfy our energy needs. Anaerobic digestion is a viable method for producing bioenergy in the form of biogas from biomass. The anaerobic digestion process is challenged with low biogas recovery, and low-quality effluent or CO2 emission, which contribute to environmental pollution and the carbon footprint in the atmosphere. Computational process modelling and simulation can provide realistic information for dealing with the technological challenges involved with anaerobic digestion. In this study, modeling and simulation of the simplified anaerobic digestion process were done using SuperPro Designer software fed with biomass feedstock containing carbohydrates, proteins, and fats, as well as yeast, at 37 °C mesophilic temperature. The anaerobic digestion process yielded 89.655% of CH4 and 10.345% of CO2 and confirmed that the carbohydrate feedstock produces more CH4 composition in the biogas. Mineralization of CO2 using MgO yielded 0.23% MgCO3, consuming > 99% of the CO2 produced during the anaerobic digestion process. Environmental impact assessment of the effluent discharge yielded 0.142 kg Slds/L volatile solid with 6.01% COD reduction per batch of the anaerobic digestion process in an anaerobic digester with 90% (1.925 kg/batch) feedstock dosage. The data indicate that single-batch effluent cannot be discharged into the environment, hence indicating the possible recycling for multiple anaerobic digestion processing. The results are a significant guide for the realistic scalable production of high-quality biogas for bioenergy application, CO2 mineralization, and environmental remediation. PubDate: 2023-04-07
Abstract: Abstract Nowadays, addressing the drawbacks of liquid electrolyte-based batteries is a hot and challenging issue, which is supposed to be fulfilled through solid electrolyte systems such as polymer electrolytes. Polymer blend electrolytes (PBEs) are widely investigated as viable options to solve the undesired characteristics of their liquid counterparts and also the poor ionic conductivity of homopolymer-based electrolytes. Even though PBEs outperform homopolymer-based electrolytes in terms of performance, the conductivity of pristine PBEs is quite low for practical applications (i.e. below 10–3 S/cm at room temperature). A very promising approach to solve this limitation is to incorporate additives into the electrolyte systems, to select suitable polymeric materials and to employ the desired synthesizing techniques as the performance of PBEs is strongly dependent on the selection of polymeric materials (i.e. on the inherent properties of polymers), the nature and amount of salts and other additives, and also the techniques employed to synthesize the polymer blend hosts and/or polymer blend electrolytes, determining the functionality, amorphousness, dielectric constant, dimensional stability, and, ultimately, the electrochemical performances of the system. This paper reviews the different factors affecting the miscibility of polymer blends, PBEs synthesizing techniques, the thermal, chemical, mechanical and electrochemical characteristics of PBEs, and also the challenges and opportunities of PBEs. Moreover, the paper presents the current progress of polymer blend electrolytes as well as future prospects for advancing polymer blend electrolytes in the energy storage sectors. PubDate: 2023-03-31
Abstract: Abstract In this study, new polypyrrole films (ppy) were synthesized using a physical plasma deposition (PAPVD) system; where the equipment design and methodology for plasma-assisted pyrrole polymerization were improvement. The morphology, functional groups, and thermal stability of the polymer network films were characterized by X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) techniques, respectively. The electrochemical properties of the films as capacitor were evaluated by cyclic voltammetry and electrochemical impedance spectroscopy. The results observed by SEM showed that the ppy 100W-1 and ppy 100W-2 films present uniformity in their structure. The analyses of TGA and DSC confirmed the improvement in stability; meanwhile for 100W-1 film, the presence of ppy bonds was corroborated by XPS. Plasma-activated ppy 100W-1 film exhibited higher capacitance and minor Rct resistance than that obtained for ppy 100W-2 film. The specific capacitances values of ppy 100W-1 and ppy 100w-2 films are 196 and 150 F/g in 1 M KCl. After charging and discharging tests of 1000 cycles at 5 mA cm−2 current density of ppy 100W-1 film retains 89% of its initial capacitance. Therefore, ppy 100W-1 film showed to be a promising material for use as an electrochemical capacitor. PubDate: 2023-02-21
Abstract: Abstract Doping TiO2 with noble metals, transition metals, cations, anions have yielded very promising results in enhancing photocatalytic activity of TiO2 in the visible region and its role in generating alternate forms of energy. Noble metals in general can effectively slow down carrier recombination. However, the study of Pd and Ni as dopant can lead to a reliable and versatile TiO2-modified photocatalyst. In this paper, we explore the optical properties of Pd- and Ni-doped TiO2 by doping with 4.17% Ni and Pd dopant concentrations. The optical properties prove that Ni-doped TiO2 can absorb well in the visible region with an absorption coefficient of 1 × 105 cm−1. Hence, Ni-doped TiO2 can successfully alter the electronic and optical properties of TiO2 for favorable future applications. In the visible region, absorption coefficient of Pd-doped TiO2 supercell is around 1.2 × 105 cm−1 which is comparatively greater than that of pure TiO2 confirming its utility as a versatile and viable visible light photocatalyst. The other optical properties like reflectivity, refractivity, extinction coefficient and electron energy loss spectrum have also been studied. PubDate: 2023-02-16
Abstract: Abstract The primary goal of the current study is to improve the specific capacitance of electric double-layer (EDLC) device using biomass (Tribulus Terrestris) derived activated carbon electrodes synthesized by chemical activation method. Furthermore, high surface area carbon electrodes are characterized using X-ray diffraction (XRD), RAMAN spectroscopy, and scanning electron microscopy (SEM) to confirm the morphological structure. Finally, the electrochemical performance of fabricated EDLC proves a good agreement data using Cyclic Voltammetry (CV), Low Impedance Spectroscopy (LIS), and Galvanostatic Charge–Discharge (GCD) analysis showing the high specific capacitance of 115 Fg−1 for the optimized 1:2 activated carbon material. PubDate: 2023-01-20
Abstract: Abstract This research work aims to study photovoltaic systems that generate energy for self-consumption using different traditional technologies, such as silicon, and emerging technologies, like nanowires and quantum. The photovoltaic system without batteries was implemented in a residential property in three different places, in Portugal. According to Portuguese Law, the sale of surplus energy to the grid is possible but the respective value for its selling is not defined. To evaluate the project viability, two different analyses are considered: with and without the sale of surplus energy to the grid. Results show that if there is no sale of excess energy produced to the grid, the project is not economically viable considering the four different technologies. Otherwise, using traditional technologies, the project is economically viable, presenting a payback time lower than 10 years. This shows that the introduction of nanostructures in solar cells is not yet a good solution in the application of solar systems namely with the current law. Furthermore, independently of the used technology, the current Portuguese law seems to difficult the investment return, which should not be the way to encourage the use of renewable sources. PubDate: 2023-01-16
Abstract: Abstract Zinc oxide is one of the most researched semiconductors owing to the outstanding properties that make it useful in various industrial applications, such as solar cells and other optoelectronics. In this work, ZnO thin films were prepared in five different concentrations and doped with four nitrogen atoms from triethylene tetramine (TETA) to fabricate a ZnO for optoelectronic applications using an electrodeposition technique. The doped ZnO thin films were synthesized and deposited on ITO glass substrates. The deposited thin films were annealed at 400°Cfor 60min in a furnace under the same conditions. The thin films' optical, electrical, and surface morphological properties were characterized using UV–Vis Spectrophotometer, Four Point Probe (FPP), and Scanning Electron Microscope (SEM), respectively. The optical properties confirmed the film's suitability for various transparent device applications with a high optical transmittance of about 90% at the wavelength between 250 and 950 nm. The optical band gaps of 3.25 eV to 3.50 eV were obtained at ZnO concentrations from 0.2 M to 1.0 M. The SEM images depicted a polycrystalline nature of the films with irregular nanoparticle shapes across the substrates. Electrical results established the high conductivity of nitrogen-doped ZnO thin films, thereby making the thin films suitable as transparent conducting oxides for devices such as solar cells and optoelectronics. PubDate: 2022-12-26
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