Low-cost Materials Research Articles

Zero-Valent Iron-Supported Magnetic Hydrochar Derived from Kitchen Waste for Efficient Fenton-like Degradation of Tetracycline Hydrochloride

In this study, hydrochars loaded with iron species (Fe@HTC and Fe@HTC−T) were prepared by chemical co-precipitation and tubular furnace sintering treatment to develop efficient and sustainable catalysts for antibiotic wastewater treatment, addressing key challenges in sustainable environmental management. The characterization results indicated that iron species loaded on the hydrochars changed from Fe3O4 to FeO and then to metallic Fe with the pyrolysis temperature increased from 400 °C to 800 °C. The results of the characterization revealed a phase transition of iron species, confirming the temperature-dependent evolution of catalytic activity. The catalytic performance of the hydrochar composites was evaluated for tetracycline hydrochloride (TC−HCl) degradation via a Fenton-like process. Under optimal conditions (0.2 g/L TC−HCl, 0.1 g/L catalyst, 0.1 mM H2O2, pH = 6.86), Fe@HTC−T demonstrated excellent catalytic activity with a removal efficiency of 91.2%. Moreover, Fe@HTC−T exhibited superior stability and low iron leaching rates, attributed to the protective role of the hydrochar matrix. Mechanism research suggested that hydroxyl radicals (•OH) played a dominant role in the degradation process. This study demonstrates the potential of utilizing low-cost and renewable hydrochar materials derived from biomass waste to address industrial challenges in treating high-concentration antibiotic wastewater, offering a sustainable and cost-effective solution with broad applications in environmental remediation.

ECONOMIC VALUATION OF ILLEGAL BRAZILIAN AMAZON DEFORESTATION: A FRAMEWORK BASED ON HABITAT EQUIVALENCY ANALYSIS AND ECOSYSTEM SERVICES RESTORATION

This work introduces a framework for assessing the economic value of illegal clearings in the Amazon primary rainforest based on Habitat Equivalency Analysis and the restoration of suppressed ecosystem services (ES). The framework ensures ES restoration in both quantity and quality, considering past and current losses as well as future gains adjusted for discount rates to present values. The translation of ES restoration into economic values is grounded in local market values, striving to ensure the results are both representative and accurate. The application of the framework in 10 ha of illegally cleared Amazon primary rainforest resulted in an economic valuation of 2022 Int.$ 341,611, or 2022 Int.$ 3175 per hectare per year, which is 35 % higher than valuations based solely on timber and cleared area restoration. The framework is sensitive to compensation period, discount rate, and ES recovery curve, leading to economic effects on the valuation of the illegal clearings in the Amazon primary rainforest. The framework is distinguished by its low human, material, and temporal costs, making it applicable even in preliminary environmental assessments. By describing the tangible economic value of Amazon primary rainforest illegal clearings, the framework allows for critical comparison with existing literature on tropical forest values, aiming to enrich society's comprehension of the costs and benefits of Amazon deforestation.

Impact of ultrasonic pretreatment on pumpkin seed protein: Effect on protease activities, protein structure, hydrolysis kinetics and functional properties.

Adding value to food by-products, such as pumpkin seeds, is an important strategy for the complete utilization of plant foods and advancing sustainability goals. This study aimed to maximize the production of bioactive peptides from pumpkin seed protein (PSP) by combining ultrasonic (US) pretreatment (40kHz, 23.8W/L) with enzymatic hydrolysis. The PSP's structure after sonication and its effects on the commercial proteases (Brauzyn®, Flavourzyme®, Neutrase®) activity and degree of hydrolysis were studied. The hydrolysis consequences regarding solubility and antioxidant activity of the resulting peptides were also evaluated. Sonication of PSP increased enzymatic activity by up to 21.3% for Brauzyn®, 24.8% for Flavourzyme® and 19.2% for Neutrase®. Consequently, there was an increase in the degree of hydrolysis (up to 89%) using sonicated PSP, particularly at 60min/40°C. These effects can be attributed to ultrasound-induced protein conformation changes, including increased intrinsic fluorescence intensity (<22%), shifts in UV spectra, and alterations in FTIR amide bands, especially a decrease in β-sheet content (<7.14%). Additionally, ultrasonic pretreatment reduced particle size (<43.9%) and polydispersity index (<58%), enhancing enzyme accessibility by fragmenting protein aggregates, as observed via scanning electron microscopy. As a result, the peptides obtained from the hydrolysis of sonicated PSP exhibited higher protein solubility (12% to 49% at pH 6.0) and improved antioxidant activity (5.6% to 77%). Overall, sonication of PSP for 60min at 40°C followed by hydrolysis with Neutrase® proved to be the most effective strategy for producing highly soluble peptides with enhanced antioxidant properties, highlighting the potential of ultrasound as a valuable tool for optimizing bioactive peptide production. Based on these results, the developed process is ready for scale-up by the food industry, aiming to obtain protein hydrolysates with improved functional and/or nutritional properties from a low-cost raw material. In parallel, further researches can focus on the potential application of these hydrolysates as ingredients in bakery, meet or dairy products.

Homebuilt cost-effective nitrogen blowdown evaporator.

Nitrogen blowdown evaporation (NBE) is a widely used technique for solvent removal. It is explicitly called for in the procedures for a wide range of analytical methods developed by regulatory and scientific agencies, and stands as a valuable tool in the sample preparation toolbox. However, commercially available equipment to perform NBE can be quite expensive, especially while working through different approaches to sample handling in the early stages of a research or analysis project. This paper details the design and construction of a homebuilt nitrogen blowdown evaporator with conventional and low-cost materials and processes, coming in at ∼20% the cost of commercial equipment. A proof-of-function experiment was carried out using the apparatus to evaporate a solution containing three per- and polyfluoroalkyl substances (PFAS). This study showed that: (1) the careful selection of materials in the design of the apparatus avoided detectable background contamination; (2) the apparatus functioned with little to no analyte loss (recoveries of 99-100% after blowdown and solvent reconstitution); and (3) evaporation times compared favorably with other designs and applications of NBE hardware. Adaptations of the apparatus for different sample containers are discussed. The ESI† includes plans and detailed instructions for the assembly and operation of the apparatus.

Enhancement of Thermal Conductivity of Paraffin PCM with Metal Foams

Paraffin PCMs (Phase Change Materials) are widely used for thermal energy storage due to their homogeneity and stability. However, one of their main drawbacks lies in their poor thermal conductivity, usually around 0.2 W·m−1·K−1. In the context of the Horizon Europe project “ECHO” (Efficient Compact Modular Thermal Energy Storage System), the integration of metal foams within paraffin PCM was investigated in order to increase the overall thermal conductivity, thus speeding up the melting and solidification phases. Tests were carried out in a thermostatic bath using at first pure aluminum foam. Then, considering the consistent price these materials usually have, other commercial and much cheaper foams were also tested, namely a stainless-steel foam and a brass one. As expected, pure aluminum had the best performance among the three foams. However, the behavior of the brass foam was quite close to that of pure aluminum, which means that interesting improvements can be achieved even with low-cost materials. As regards the stainless-steel foam, barely any improvement is observed.

Designing and manufacturing a flexible heel of a printed prosthetic foot for rehabilitation

AbstractThe prosthetic feet available in the market are characterized by high costs and are made of carbon fiber materials, fiberglass, or silicone-coated wood. This study aims to design and manufacture a prosthetic foot to enhance biomechanical performance and user comfort and mimic the natural movement of the human foot; the foot will be designed and manufactured from low-cost materials, namely carbon fiber filaments, using 3D printer technology. The practical part consists of tensile, fatigue tests, and manufacturing the foot using a 3D printer. In this study, the ANSYS program will also analyze the designed model numerically to determine the stresses generated when applying the assumed body weight to the foot model. The results showed that the model is successful in terms of design and does not suffer any mechanical failure during use, in addition to the success of the selection of the material used in the manufacturing process due to its mechanical properties, where the yield stress value = 36.4 MPa, the ultimate stress value = 58.39 Mpa and Young's modulus = 1.23 GPa.

Shielding effectiveness of high-polymer short-staple-based fabric implanted with the metamaterial structure of “split ring resonator”

PurposeElectromagnetic shielding (EMS) fabrics composed of cotton, polyester and other high-polymer short-staple fibers are widely utilized in various fields. However, the inevitable pores in these fabrics lead to the leakage of electromagnetic waves, which severely diminishes the fabric’s shielding effectiveness (SE). To address this issue, this paper proposes the implantation of a metamaterial structure known as the “split ring resonator (SRR)” into the fabric.Design/methodology/approachFirstly, the types and principles of SRRs are analyzed. Through electromagnetic simulation and emulation, the effectiveness of SRRs in dissipating electromagnetic waves is confirmed. By selecting different embroidery methods, various shapes of SRRs are implanted into the fabric. Subsequently, through testing and analysis of sample fabrics embroidered with SRRs, it is concluded that implanting appropriate SRRs into pure cotton fabrics and cotton/polyester/stainless steel-blended EMS fabrics can effectively impart or enhance the SE of these fabrics.FindingsFor pure cotton fabric without inherent SE, the peak SE value can reach over 30 dB within the 6.57 GHz–7 GHz frequency band, and the minimum SE is greater than 10 dB in the 7 GHz–9.99 GHz frequency band. For the cotton/polyester/stainless steel-blended EMS fabric, the improvement in SE across all frequency bands exceeds 10 dB, averaging around 15.6 dB. The circular type SRR demonstrates the most significant improvement in fabric SE. When the substrate is composed of pure cotton or a cotton/polyester/stainless steel blend, the circular SRRs provide an average enhancement of more than 4 dB and 6 dB, respectively, than other shapes. The fewer the holes created by the implantation method, the higher the SE of the fabric after SRR implantation, with the invisible embroidery technique being the most effective. It improves the fabric’s SE by an average of about 2 dB more than flat embroidery and can be up to an average of around 6 dB higher than the backstitch embroidery technique. For every 0.2 cm increase in the size of the SRRs, the average SE increases by about 4 dB, and for every 0.5 cm increase in the spacing between them, the fabric’s SE decreases by an average of more than 2.7 dB.Originality/valueThis paper offers a novel approach to counteract the issue of pores reducing the SE of EMS fabrics and provides a new method for developing lightweight, thin, low-cost and high-performance EMS fabric composite materials.

Acid Pre-Treatment of Graphite Electrodes: An Alternative to Enhance the Sensing Performance of Benzenediol Isomers

Abstract Electroanalytical techniques offer several advantages, such as low cost, portability, and high analysis frequency. These benefits can be further enhanced by replacing standard electrodes (boron-doped diamond, glassy carbon, gold, platinum, etc.) with abundant, low-cost carbon materials. Pyrolytic Graphite Sheet (GS) electrodes have recently emerged as a reliable alternative, providing good stability, sensitivity, and mechanical strength. Their performance can be improved with acidic treatments. Scanning electron and atomic force microscopy images revealed irregular patterns on the edges of acid-treated GS, consistent with Raman spectra, which showed changes in the ID/IG ratio, indicating more structural defects. The acidic treatment also increased the electroactive area of GS electrodes and oxygen-containing functional groups, as observed by XPS, leading to enhanced signal currents. Additionally, electrochemical impedance spectroscopy confirmed a decrease in charge transfer resistance. Treated electrodes exhibited lower detection limits for catechol (0.58 µmol L-1) and resorcinol (0.16 µmol L-1) compared to untreated GS electrodes. The presence of potential interferents, such as KCl, NaCl, glucose, ascorbic acid, ibuprofen, paracetamol, and uric acid, did not affect the detection of catechol and resorcinol. Recovery values for spiked water samples ranged from 80% to 109%, confirming the accuracy of the proposed analytical method.

Comprehensive review of modeling and material selection for hybrid sandwich composites for ballistic impact application using Six Sigma DMAIC methodology

Natural fiber-based PMC (polymer matrix composites) have recently been increasingly popular because of their reduced product weight, low material costs, and renewable sources. Hybrid composites with different combinations of fibers/matrix are attracting interest from many manufacturing industries and researchers for various applications because of their specialized mechanical and impact properties. Hybridization is one of the most essential and indispensable strategies to improve composite material performance. Hybrid sandwich composites are reviewed to enhance the mechanical properties. They mainly concentrate on improving impact properties with increased energy absorption and penetration behavior, making them competent for advanced applications. The most time-consuming and challenging task is identifying the suitable composite material for a specific application. Selecting a suitable fiber and matrix is a difficult job for impact applications because the impact can cause severe damage to composite used in structural applications. The main objective of this review is to select suitable fiber and matrix combinations for impact application by exploring the literature gap. The Six Sigma DMAIC methodology provides a different approach to the selection of material. The benefit of this methodology is the choice of material has been made based on a twofold decision-making process that provides an accurate result. In addition to this blending, the qualitative approach (Pugh method) and the quantitative approach (Analytical hierarchy process) produce more accurate results during the comparison process, making it easier to choose the best material.

Sustainable Approach to Utilization of Waste Glass Fibers and Basalt Powder as Potential Additives in Epoxy-Based Composites for Reparation of Concrete Structures

The growing production of glass fibers is a major challenge due to the later problem of their sustainable recycling. This article reports the potential use of post-production waste glass fibers and basalt powder as additives in resin compounds designed for repairing concrete elements. The aim of this research was to develop a repair compound based on epoxy resin with the addition of waste materials, offering a competitive alternative to currently available repair compounds on the market by utilizing lower-cost materials and addressing pro-environmental aspects through waste reuse. The prepared research samples were characterized by varying proportions of basalt powder (0–20%), ground HP 12 fibers (40/60%), and HP 6 fibers (10/20%). A series of tests, including tensile strength tests, were conducted as part of this study to determine the effect of the applied additives on the ultimate tensile force and maximum deformations. Abrasion resistance tests were also carried out to evaluate the impact of basalt powder as a filler on enhancing the abrasion resistance of the designed repair compound. Additionally, SEM and EDS analyses were used to evaluate the uniformity and distribution of the additives within the sample. This study examined samples containing varying percentages of basalt powder and fibers, both virgin and milled. The most significant reinforcement effect was observed for sample E/20HP/20bp, where its tensile strength decreased by 8%, while its abrasion resistance increased by 44% compared to the reference sample. The obtained results confirm that incorporating waste materials as additives into epoxy resin can significantly enhance the mechanical properties of repair compounds while reducing cost and promoting environmental protection. In addition, the repair compound developed complies with the selected principles within the 6Rs environmental regulations: RECYCLING (reuse of waste glass fibers), RETHINK (reduce environmental impact by avoiding landfill), REDUCE (minimize the use of virgin glass fibers in the production of repair compounds) and REPAIR (increase the efficiency of repairing damaged concrete structures). Furthermore, as the percentage of basalt powder increases, the abrasion resistance of the repair compound improves. The obtained repair compounds may serve as an alternative to currently used compounds for the repair of bridges and factory floors.

A catalyst-coated diaphragm assembly to improve the performance and energy efficiency of alkaline water electrolysers

Alkaline water electrolysers are ideal for gigawatt-scale hydrogen production due to the usage of non-precious metal and low-cost raw materials. However, their performances are modest with the separated electrode and diaphragm structure which can date back to more than 100 years ago. Here we report a catalyst-coated diaphragm assembly to improve the performance of alkaline water electrolysers. The transport resistance of OH- ions is reduced and the electrochemical surface area of catalysts is enlarged by more than forty fold, representing more than 40% increase in hydrogen production rate or as much as 16% reduction in energy consumption. The electrolyser with our catalyst-coated diaphragm assembly delivers current densities as high as 1 A cm−2 at 1.8 V or 2 A cm−2 at 2 V and shows good stability after more than 1000 hours of operation. Therefore, the catalyst-coated diaphragm assembly route is promising for the development of high-performance and efficient alkaline water electrolysers.

Application of biomanufacturing in polymer flooding

In China, the crude oil supply is highly dependent on overseas countries, and thus strengthening crude oil self-sufficiency has become an important issue of the national energy security. Tertiary oil recovery, especially polymer flooding, has been widely applied in large oil fields in China, which can increase the recovery rate by 15%-20% compared with water flooding. However, the widely used oil flooding polymers show poor thermal stability and salinity tolerance, complicated synthesis ways of monomers, and environmental unfriendliness. Moreover, the polymer flooding induces problems including pore plugging, heterogeneity intensification, high dispersion of remaining oil resources, pressure rise in injection wells, and low efficiency circulation of injection medium, which restrict the subsequent recovery of old oil fields. Here, we systematically review the developing and current situations of polymer flooding, introduce the innovative biomanufacturing of oil flooding polymers and their monomers or precursors as well as low-cost bio-based chemical raw materials for multiple compound flooding. The comprehensive study of the relationships between microbial fermentation metabolites and polymer flooding will reveal the green and low-carbon paths for polymer flooding. Such study will enable the application of enzymes produced by microorganisms in polymer production and polymer plugging removal after polymer flooding as well as the application of microbial metabolites such as biosurfactants, organic acids, alcohols, biogas, and amino acids in enhancing oil recovery. This review suggests that incorporating biomanufacturing into polymer flooding will ensure the high productivity and stability for crude oil production in China.

Application of Ultrafast Lasers: A Promising Route toward the Fabrication of Advanced Perovskite‐Based Devices

AbstractPerovskite materials have received considerable research attention owing to their high carrier mobility, photoluminescence quantum yield, and light absorption coefficient. Their excellent optoelectronic properties and low material costs make them a strong competitive raw material for future electronic and high‐temperature superconducting materials. In particular, when applied to light‐emitting diodes (LEDs) and solar cells, their high conversion efficiency and relatively simple preparation process make them revolutionary materials that may change the pattern of perovskite‐based devices and overcome the limits of industrialization. However, with the development of technology, traditional preparation and treatment methods for perovskites no longer meet the increasing demands of the industry. Laser technology is widely used owing to its remarkable compatibility with perovskite materials. Therefore, this review summarizes the applications of laser technology to perovskite materials, including laser‐induced nucleation and film formation, laser annealing, laser ablation, laser printing, and laser patterning, discusses the achievements of researchers in using laser technology to regulate perovskites in recent years, and highlights the prospects of perovskite‐based laser technology.

Bibliometric Analysis on Graphitic Carbon Nitride (g-C3N4) as Photocatalyst for the Remediation of Water Polluted with Contaminants of Emerging Concern

Carbon nitrides are polymeric materials with a broad range of applications, including photocatalysis. Among them, graphitic carbon nitride (g-C3N4), a low-cost material, is an excellent photocatalyst under visible light irradiation owing to its features such as correct band positions, high stability and non-toxicity. g-C3N4 is a metal-free material that is easily synthesized by polymerizing nitrogen-rich compounds and is an efficient heterogeneous catalyst for many reaction procedures due to its distinctive electronic structure and the benefits of the mesoporous texture. In addition, in situ or post-modification of g-C3N4 can further improve catalytic performance or expand its application for remediating environmental pollution. Water pollution from organic compounds such as pesticides and pharmaceuticals is increasing dramatically and is becoming a serious problem around the world. These pollutants enter water supplies in a variety of ways, including industrial and hospital wastewater, agricultural runoff, and chemical use. To solve this problem, photocatalysis is a promising technology. Without the use of other oxidative chemicals, g-C3N4 uses renewable solar energy to transform harmful pollutants into harmless products. As a result, much recent research has focused on the photocatalytic activity of g-C3N4 for wastewater treatment. For this reason, the main objective of this paper is to contribute a chronological overview of the bibliometrics on g-C3N4 for the removal of pesticides and pharmaceuticals from water using the tools BibExcel, Bibliometrix and R-Studio IDE. A bibliometric analysis was performed using the Science Citation Index Expanded (WoS©) database to analyze the scientific literature published in the field over the last 10 years. The results were used to identify limitations and guide future research.

Thiophene Copolymer Donors Containing Ester-Substituted Thiazole for Organic Solar Cells.

Organic solar cells have seen significant progress in the past 2 decades with power conversion efficiencies (PCEs) exceeding 20% but mostly based on high-cost photovoltaic materials. Polythiophenes (PTs) without a fused-ring structure are good candidates as low-cost donor materials, deserving more attention for studying. In this work, ester-substituted thiazole (E-Tz) was explored as the electron-withdrawing unit to design PTs, and further optimization on the fluorinated/nonfluorinated donor segment contents via copolymerization strategy was simultaneously performed, yielding polymer donors of PTETz-100F, PTETz-80F, and PTETz-0F. Suitable temperature-dependent aggregation for reasonable phase separation and compact molecular packing for improved charge transport were achieved in the PTETz-80F-based system, resulting in higher exciton dissociation probability and charge collection probability. Thereby, devices based on PTETz-80F:L8-BO exhibited the best photovoltaic performance with a PCE of 12.69%. In addition, the synthetic complexity of PTETz-XF polymers is 46.05%, which is significantly lower than those of other representative high-performance polymer donors. This work demonstrates the feasibility of designing PTs with an E-Tz unit and the effectiveness of the copolymerization strategy on material property and device performance optimization.

Halide perovskites, a game changer for future medical imaging technology.

The accurate detection of x-rays enables broad applications in various fields, including medical radiography, safety and security screening, and nondestructive inspection. Medical imaging procedures require the x-ray detection devices operating with low doses and high efficiency to reduce radiation health risks, as well as expect the flexible or wearable ones that offer more comfortable and accurate diagnosis experiences. Recently, halide perovskites have shown promising potential in high-performance, cost-effective x-ray detection owing to their attractive features, such as strong x-ray absorption, high-mobility-lifetime product, tunable bandgap, fast response, as well as low-cost raw materials, facile processing, and excellent flexibility. In this review, we comprehensively summarize the recent advances in halide perovskite x-ray detectors and imaging, focusing on their application potential in medical imaging technology. We highlight the recent demonstrations and optimizations of halide perovskite x-ray detectors and imaging and their application in medical radiography. Finally, we conclude by pointing out the challenges of perovskite x-ray detection devices for the clinical practical applications and by sharing our perspectives on the potential solutions for driving the field forward.

Performance efficiency of locally available low-cost adsorbents in purification of biogas for high grade applications

Despite having several benefits, the uptake of biogas as a green fuel in rural areas has remained low. One of the technical challenges responsible for slow biogas adoption rate in rural households is biogas contamination. Biogas requires treatment before use, this includes; purification and upgrading. Purification involves the removal of impurities whereas upgrading aims to convert the biogas to a higher fuel standard by increasing its low calorific value. The aimof this study was to develop and test the performance of a cost-effective and affordable system for purification of biogas using low-cost absorbents, thus upgrading biogas to a sustainable clean cooking fuel. The study employed an experimental research design. A pilot domestic scale biogas cleaning system was set up at the Jomo Kenyatta University of Agriculture and Technology (JKUAT) IEET workshop. The study sought to determine the potential and efficiency of locally available and low-cost adsorbents in purification of raw biogas. The raw biogas was passed through the cleaning units, each packed with individual adsorbent. Analysis ofthe biogas for methane (CH4) composition was done before and after each cleaning unit using digital biogas analyzer model GASTiger 2000, supplied by Yantai Stark Instrument Company limited. The locally available low-cost adsorbents used in the study were; red soil, charcoal, steel wool, clay soil, iron shavings and wood ash. This study also tested the effect of the various physical interfaces of the adsorbents, where a cleaning unit packed with two or more of the adsorbents was used. The study shows that adsorption by clay soil and charcoal gave highest methane concentrations at 67.48±2.33% and 67.20±1.08% respectively from 58.47±2.12% in raw biogas. Cleaning by the other adsorbents; red soil, wood ash, steel-wool and iron shavings improved methane concentrations to 61.76±0.71%, 60.75±2.47%, 58.97±1.92% and 58.56±1.96% respectively. Combination of the various adsorbents into one cleaning unit further improved methane levels to 69.83±1.57%. These results, despite exhibiting relatively low adsorption of the impurities in raw biogas, positively confirmed that indeed the low-cost adsorbent materials have a potential in biogas purification. Modification of these low-cost adsorbent materials, such as use of activated charcoal, would be one of the ways to improve their performance. However, this study specifically sought to explore the potential of these low-cost adsorbents in purification of raw biogas, in their natural state. This study recommends further exploration of other relatively less technical methods such as water scrubbing that could be coupled with the use of natural low-cost adsorbents to improve the purification of raw biogas to near, if not equivalent to, natural gas (that is in the regions of 97-100% CH4 concentration). Thus, for a possible adoption as an alternative means of cleaning and upgrading raw biogas to a clean cooking fuel.

High-Energy Aqueous Sodium-Ion Batteries Using Water-in-Salt Electrolytes and 3D Structured Electrodes.

Aqueous sodium-ion batteries (SIBs) are gradually being recognized as viable solutions for large-scale energy storage because of their inherent safety as well as low cost. However, despite recent advancements in water-in-salt electrolyte technologies, the challenge of identifying anode materials with sufficient specific capacity persists, complicating the wider adoption of these batteries. This study introduces an innovative and straightforward approach for synthesizing vanadium oxide laser-scribed graphene (VOx-LSG) composites, which function as effective anode materials in aqueous sodium-ion batteries. By combining a rapid laser-scribing technique with precise thermal control, the method not only allows for changing the morphology of the vanadium oxide, but also tuning its oxidation state. This is achieved while embedding these electrochemically active particles within a highly conductive graphene scaffold. When paired with a Prussian blue-based cathode (Na1.88Mn[Fe(CN)6]0.97) in a concentrated NaClO4-based aqueous electrolyte, the battery's charge storage mechanism is found to be largely surface-controlled, leading to exceptional rate performance. The full cell demonstrates specific capacities of 128 mA h/g@0.05 A/g and 65.6 mA h/g@1 A/g, with an energy density of 47.7 W h/kg, outperforming many existing aqueous sodium-ion batteries. This strategy offers a promising path forward for integrating efficient, eco-friendly, and low-cost anode materials into large energy storage devices and systems.

Interfacial diffusion enabled broadband response in photodetector based on In2Se3/GaAs heterojunction.

Infrared (IR) photodetectors play a crucial role in modern technologies due to their ability to operate in various environmental conditions. This study developed high-performance In2Se3/GaAs interdiffusion heterostructure photodetectors with broadband response using liquid-phase method. It is believed that an InGaAs layer and In2Se3 have been formed at the interface through the mutual diffusion of elements, resulting in a detection spectral range spanning from 0.45 to 2.7 µm. Consequently, the In2Se3/GaAs photodetector exhibits notably low noise equivalent power of 6.21 × 10-15 WHz-1/2 at 1000 Hz, high photoresponsivity (R) and detectivity (D*) of 16.22 mA/W and 4.01 × 1011 Jones under 0 V with 630 nm wavelength, respectively. At 1550 nm, it achieves a R of 0.43 µAW-1 and D*of 1.07 × 108 Jones under 0 V. This strongly suggests that the interdiffused In2Se3/GaAs heterostructure is a high performance and low-cost material for broadband responsive photodetectors.

Particle Vertical Mixing and Horizontal Conveyance Within an Ambient Temperature Fluidized Bed

Previous studies have shown the advantages of particle-to-sCO2 fluidized bed (FB) heat exchangers, which include high heat transfer coefficients, low material cost, and the ability to horizontally convey solid particles. This paper outlines the design and testing of a compact cold flow FB test apparatus to characterize horizontal conveyance through convolutions within a 100 kWth FB heat exchanger design. Horizontal conveyance is an advantage in FBs because it enables more compact designs for heat exchangers. Two mass flow rates, 0.5 &amp; 1 kg/s, at the inlet &amp; outlet of the FB. To determine consistency of the flow rates, Student’s t-tests were used to assess whether the inlet &amp; outlet values were statistically similar. The mass flow rate exiting the bed was statistically similar to the flow rate entering the bed for both cases, but each case featured a wider range and standard deviation. The range and standard deviation of the 1 kg/s flow rate was 0.69-1.23 kg/s and 0.12 kg/s respectively, and the 0.5 kg/s test featured a range and standard deviation of 0.37-0.73 kg/s and 0.09 kg/s, respectively. These measurements provide confidence that large-scale designs can successfully horizontally convey particles at ````~1.5x minimum fluidization velocity (U­mf) without significant variation in flow rate. A method to characterize the degree of particle vertical mixing and bubble frequency within the FB is also introduced. By using a high-resolution camera together with particle velocimetry, particle motion in the X and Y directions can be estimated to assess bed mixing and bubble frequency.