Materials for Renewable and Sustainable Energy最新文献

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.

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 (V_OC- 2.750), short-circuit current density (J_SC- 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.

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 (V_oc), short-circuit current density (J_sc), 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.

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 SnO_2, 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.

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.

Aqueous zinc-ion batteries (AZIBs) are considered to be highly promising electrochemical energy storage device due to their affordability, inherent safety, large zinc resources, and optimal specific capacity. Among various cathode materials, manganese dioxide (MnO₂) stands out for its high voltage, environmental benignity, and theoretical specific capacity. This study systematically investigates the phase formation and structural parameters of α-MnO₂, β-MnO₂, and δ-MnO₂ synthesized via hydrothermal method, employing Rietveld refinement. FTIR and Raman spectroscopy confirms Mn-O and O-H bond formation. BET analysis reveals surface areas, and pore size distribution is calculated with BJH method. High-resolution XPS spectra exhibit a spin energy split of ~ 11.9 eV for Mn 2p confirming the presence of MnO₂. Electrochemical studies shows an initial discharge capacities of 230.5, 188.74 and 263.30 mAh g^− 1 at 0.1 A g^− 1 for α-MnO₂, β-MnO₂ and δ-MnO₂. The EIS spectra revealed the capacitive behaviour and electrode reaction kinetics where a R_cT value of 484.14, 327.6, 162.5 Ω for α-MnO₂, β-MnO₂ and δ-MnO₂. These study give insights into relation of various properties of MnO₂ with electrochemical performance and its viability in grid storage applications.

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The advent of long-term implants has increased the urgent need for self-powered biomedical devices. Utilize enzymes to expedite the process of biofuel oxidation. These systems frequently make use of glucose oxidase. A possible solution involves glucose biofuel cells powered by the glucose found in physiological fluids. Biocompatible substances like carbon electrode designs help to transport electrons from the biological reactions to the external circuit as efficiently as possible while maximizing surface area. Despite advances in implantable electrodes, developing miniaturized and flexible electrodes remains challenging. In this work, a metal-coated flexible carbon thread and foam bioelectrode are fabricated and successfully implanted inside a living and freely moving rat. These electrodes are prepared using gold nanostructures as electron enhancers, a negatively charged conducting polymer, a biocompatible redox mediator, and enzymes as biocatalysts. The carbon foam-based enzymatic biofuel cell produces in vitro and in vivo settings, generates a power density of 165 µW/cm² and 285 µW/cm², and the carbon thread-based fuel cell produces a power density of 98 µW/cm² and 180 µW/cm² in vitro and in vivo environments, respectively. This work paves the way for the possible use of inexpensive electrodes for subdermal implantable microsystems.

The increasing demand for cost-effective materials for energy storage devices has prompted investigations into diverse waste derived electrode materials for supercapacitors (SCs) application. This review examines advancements in converting waste into carbon-based SCs for renewable energy storage. In this context, different carbon-based waste precursor sources have been explored over the years as electrodes in SCs. These waste sources comprise of industrial, plastics and biowastes, including plant and animal wastes. The energy storage capabilities of the various waste derived SCs electrodes are highlighted to provide an understanding into the unique features that make them applicable to SCs. In addition, some challenges associated with the waste-derived SCs electrodes in terms of energy storage have been emphasized. Here, we also provided insights into the recent progress in SCs electrode synthesis techniques and their effects on electrochemical performance. SCs performance tailoring with material structures through the incorporation of different materials to form composites and optimized synthesis methods is an effective strategy. Hence, the synthesis methods outlined include pyrolysis, hydrothermal, microwave-assisted, template-assisted, and sol–gel techniques. The effect of the various synthesis methods on SCs performance has also been discussed. Overall, this review highlights waste valorization with future research directions and scaling challenges.

Appropriate and effective management of fruit wastes is fundamental for promoting sustainability, minimizing environmental impacts, and safeguarding human health. This underscores the necessity for sustainable waste management practices including transforming them into valuable products to mitigate their adverse effects. This study focuses on the production of bioethanol from pineapple, mango, watermelon, and pawpaw fruit wastes juice through yeast fermentation and controlled distillation. The juice from a mixture of fruit wastes was enriched with 200 g of bakery yeast to facilitate the fermentation process. Results show that bioethanol from fruit waste juice mixture with bakery yeast produced bioethanol with alcohol content of 30%, while the fruit waste juice mixture without yeast had 20%. The bioethanol from the initial distillation was combined and re-distilled to improve the quality of bioethanol from 12 to 30% to an impressive alcohol content of 88%. The bioethanol production from fruit wastes, achieved through bakery yeast fermentation and distillation, demonstrated promising outcomes and potential use as bioenergy and its contribution to environmental conservation. Future research may focus on enhancing yeast-fruit waste juice ratio and utilizing enzymes to expedite carbohydrate breakdown.

A long-term recycling strategy integrated into the circular economy of materials will be the only feasible option going forward on the use of lithium-ion batteries; the development of such a technology is critical to achieving a sustainable state of energy and waste management. Supercritical fluids are great technological candidates for recycling lithium-ion batteries and recovering cobalt which can be then integrated into a circular economy through the industrialization of an efficient recycling process. Cobalt recovery is feasible using supercritical CO₂, supercritical and subcritical water with organic acids with up to 99% efficiency.