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The proton exchange membrane fuel cells (PEMFCs) are environmentally friendly, sustainable, and excellent energy conversion systems to produce pollutant-free electricity. Generating cost-effective and promising performance electrode materials for PEMFCs is a primary requirement for generating excellent PEMFCs. Graphene and MXene-based nanomaterials are outstanding candidates for use in PEMFCs because of their exceptional characteristics. For industrial-scale applications, the PEMFCs face a few operational challenges, including limited mechanical stability, limited ion exchange capacity at elevated temperatures, low thermal stability, high cost of production, and high fuel crossover. These challenges faced by PEMFCs can be overcome by advanced graphene and MXene-based composite nanomaterials because of their excellent characteristics, including desired thermal and mechanical stability, higher specific surface area (SSA), and number of effective and active surface functional groups. The graphene-based composite materials are suitable candidates for the PEMFCs because of their promising conductivity, high current density, and cyclic capacity compared to MXene. This study provides a comparative investigation of the properties, synthesizing routes, and performance of graphene and MXene as PEMFCs' based advanced nanomaterials. In addition, the challenges and future research directions on the PEMFCs as cathode nanomaterials are also highlighted. • Mechanisms of Graphene and MXene for PEMFCs applications were narrated. • The role of and chemistry of nanomaterial for PEMFCs was discussed. • Comparative mechanisms of Graphene and MXene have been discussed. • Challenges and perspectives of Graphene and MXene have been illustrated. [ABSTRACT FROM AUTHOR]

Epoxides were primarily derived from petroleum-based sources. However, there has been limited research on optimizing the process parameters for epoxidized palm oil-derived oleic acid, resulting in its underutilization. Therefore, this study aimed to optimize the catalytic epoxidation of palm oleic acid concerning the oxirane content by applying ion exchange resin as a catalyst. Epoxidized oleic acid was produced using in-situ-formed performic acid by combining formic acid as the oxygen carrier with hydrogen peroxide as the oxygen donor. The findings revealed that the optimal reaction conditions for producing epoxidized oleic acid with the highest oxirane content were an Amberlite IR-120 catalyst loading of 0.9 g, a molar ratio of formic acid to oleic acid of 1:1., and a molar ratio of hydrogen peroxide to oleic acid of 1:1.1. By employing these optimal conditions, the maximum relative conversion of palm oleic acid to oxirane was achieved at 85%. The reaction rate constants (k) based on the optimized epoxidized oleic acid are determined as follows: k11 = 20 mol L−1 min−1, k12 = 2 mol L−1 min−1, and k2 = 20 mol L−1 min−1. The findings validated the kinetic model by showing good agreement between the simulation and experimental data. [ABSTRACT FROM AUTHOR]

Carbon nanostructure materials are becoming of considerable commercial importance, with interest growing rapidly over the decade since the discovery of carbon nanofibers. In this study, a new novel method is introduced to synthesize the carbon nanofibers by gas-phase, where a single-stage microwave-assisted chemical vapour deposition approach is used with ferrocene as a catalyst and acetylene and hydrogen as precursor gases. Hydrogen flow rate plays a significant role in the formation of carbon nanofibers, as being the carrier and reactant gas in the floating catalyst method. The effect of process parameters such as microwave power, radiation time and gas ratio of C 2 H 2 /H 2 was investigated statistically. The carbon nanofibers were characterized using scanning and transmission electron microscopy and thermogravimetric analysis. The analysis revealed that the optimized conditions for carbon nanofibers production were microwave power (1000 W), radiation time (35 min) and acetylene/hydrogen ratio (0.8). The field emission scanning electron microscope and transmission electron microscope analyses revealed that the vertical alignment of carbon nanofibers has tens of microns long with a uniform diameter ranging from 115 to 131 nm. High purity of 93% and a high yield of 12 g of CNFs were obtained. These outcomes indicate that identifying the optimal values for process parameters is important for synthesizing high quality and high CNF yield. [Display omitted] • A new route for synthesis of CNFs usng single stage MA-CVD was discussed. • Optimization of process parameters on production of CNFs using CCD was narrated. • The detailed characterization of CNFs was deliberated. • High purity (93%) and high yield (12 g) of CNFs were obtained. [ABSTRACT FROM AUTHOR]

This document is an introduction to a special issue of the Topics in Catalysis Journal titled "Sustainable Synthesis of Inorganic/Organic Nanomaterials Based Efficient and Reusable Catalysts: A Way Forward to Sustainable Development Goals." The issue explores the synthesis of inorganic and organic nanomaterials as catalysts that align with the principles of sustainability. The articles in this issue cover a range of topics, including green synthesis methodologies and strategies for the development of different nanomaterials-based catalysts. The goal is to promote reusable catalyst development to minimize waste generation and environmental impact. The document concludes with a note from the publishers expressing their commitment to neutrality and appreciation for the authors and reviewers involved in the special issue. [Extracted from the article]

This paper studies an adjacent accumulation discrete grey model to improve the prediction of the grey model and enhance the utilization of new data. The impact of COVID-19 on the global economy is also discussed. Two cases are discussed to prove the stability of the adjacent accumulation discrete grey model, which helped the studied model attain higher forecasting accuracy. Using the adjacent accumulation discrete grey model, non-renewable energy consumption in G20 countries from 2022 to 2026 is predicted based on their consumption data from 2011 to 2021. It is proven that the adjacent accumulation exhibits sufficient accuracy and precision. Forecasting results obtained in this paper show that energy consumption of all the non-renewable sources other than coal has an increasing trend during the forecasting period, with the USA, Russia, and China being the biggest consumers. Natural gas is the most consumed non-renewable energy source between 2022 and 2026, whereas hydroelectricity is the least consumed. The USA is the biggest consumer of Nuclear energy among the G20 countries, whereas Argentina consumed only 0.1 Exajoules of nuclear energy, placing it at the end of nuclear energy consumers. [ABSTRACT FROM AUTHOR]

Al-Mg-Cr alloys have been extensively used due to their inherent characteristics, including lightweight, high strength, resistance to corrosion, and recyclability. Still, the residues of various intermetallic phases cause grain boundary sliding and recrystallization at elevated temperatures, minimising their mechanical properties. This can be improved by adding suitable ceramic-strengthening particulates. The current study involved synthesizing B 4 C of varying weight proportions, retaining ZrO 2 as a constant with Al-Mg-Cr alloy using a vacuum-assisted stir casting process; an ASTM standard investigated its microstructure and mechanical properties. Microstructure observation inferred that the ceramic strengthening particles are equally disseminated, and the Cu-Al 2 , Mg 2 Si, and Zn-Al 2 eutectic precipitate at the grain boundaries of Al-Mg-Cr alloy solid solution. The mechanical properties of the 8 wt% B 4 C+ 2 wt% ZrO 2 composite were improved compared to other combinations and the as-cast Al-Mg-Cr alloy. This improvement was attributed to enhanced wettability and grain refinement, resulting in increased hardness (26 ± 0.06%), tensile strength (25 ± 0.38%), compressive strength (20 ± 0.31%), flexural strength (26.41 ± 0.02%), and impact strength (23 ± 0.03%). An ASTM B117 salt spray fog test was conducted to evaluate the corrosion resistance of the synthesized immixture. The test results indicated that the development of a protective layer of Al 2 O 3 and AlB 2 intrinsically enhances the corrosion resistance of the intermixture. • Al-Mg-Cr/B 4 C/ZrO 2 formed by vacuum assisted stir cast at 780 °C,600 rpm,150 kg/cm2. • Hybrid composites porosity was decreased to 20 ± 0.002% with more ceramic particles. • B 4 C/ZrO 2 induce pinning effects hinder dislocations increased hardness (26 ± 0.06%). • Dispersed B 4 C/ZrO 2 inhibits fracture propagation increases mechanical properties. • Al 2 O 3 and AlB 2 prevent Al-Mg-Cr alloy from corrosion up to ± 61 ± 0.004%. [ABSTRACT FROM AUTHOR]

The utilization of natural fibres often entails a lesser environmental impact when compared to synthetic fibres. Biodegradable natural fibres minimize waste and pollution, and promote sustainability, but their weaker bonds limit their resilience. These issues can be addressed by customizing the composite's mechanical properties with natural and synthetic fibres. In this study, hybrid composites were created using the hand layup method with a novel dissimilar layer arrangement of neem (N), sisal (S), and glass (G) fibre and analyze its mechanical and thermal properties. Experimental observation shows that the GN composite had a higher maximum ultimate tensile strength of 26 N/mm2 than the GS, GNS, and GSN composites. The GN composite had a percentage elongation of 6.33%, similar to the percentage elongation of the GS composite (6.833%), and it also had a higher ultimate shear strength of 50 MPa. The composite GS absorbed 6.6 J energy, higher than the composites GN, GNS, and GNS, which absorbed 6.1 J, 4.5 J, and 4.5 J, respectively. The fractured surface's SEM images were obtained and analyzed for failure. The results demonstrated that the hybridization was effective, and better properties can be obtained by combining neem, sisal, and glass fiber, and it can be used for other requirements, including strength, weight, cost, and ecological impact. [Display omitted] • GS/GN/GSN/GNS composites were fabricated using hand layup method. • The breaking load of the composite GN was found to be 2.6 kN. • The percentage of elongation of GS exhibited 6.83% compared to others. • GS absorbed 6.6 J of energy, surpassing GN, GSN, and GNS composites. • At a temperature of 700 °C GNS experienced a lower weight loss of 88.94%. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) and MXene are innovative materials of 2D heterostructured nanomaterials that evolved and found many applications. Because of the outstanding porosity, high specific surface area (SSA), environmental friendliness, structural properties, and chemical, mechanical, and thermal stability of GO and MXene are extensively utilized to manufacture Li-batteries, hydrogen storage semiconductors and water desalination membranes. The GO-based composites are superior to MXene-based composites in desalinating the water because of their excellent SSA (2391 m2/g), high mechanical strength (470 GPa), and Electrical conductivity (4.12 × 10−5 S.cm−1) and thermal conductivity (2–1000 W/mk). Compared to GO, MXene has more inferiority regarding stability and recyclability. The highest salt rejection capacity of GO-CD-PA and MXene slit membranes are 99.9 % and > 90 %, respectively. Adding polymer-based nanomaterial can enhance the salt rejection performance chemical, thermal and mechanical stability of GO and MXene. Adding polymers also positively impacts the unit-fouling characteristics of GO and MXene. The current review paper compares the physical and chemical properties of GO and MXene that have a viable impact on the desalination of the GO and MXene-based membranes. The synthesizing route is another factor that significantly impacts the structure and desalination performance of GO and MXene. Both 2D materials synthesized via traditional techniques have poor desalination capability compared to those synthesized via advanced or modified synthesizing techniques. Membrane fouling is a critical issue to limit the applications of membranes, and ways to handle these issues are addressed. This paper briefly introduces the various synthesizing techniques of GO and MXene. The basic objective of the paper is to compare the desalination performance of GO and MXene. The challenges and prospects of GO and Mxene were discussed. The authors believe this contribution addresses important and recent problems related to the desalination industry. • Comparison mechanisms of the Graphene and MXene-based membranes are highlighted. • Holistic characteristics of Graphene and MXene were narrated. • Graphene has superb desalination capability, recyclability and stability compared to MXene-based membranes. • Challenges and prospects associated with Graphene and MXene-based nanomaterial have been discussed. [ABSTRACT FROM AUTHOR]

In the present study, a vacuum-assisted stir-casting process was made to synthesize nano-molybdenum trioxide-strengthened magnesium alloy composites of varying weight proportions. Morphological analysis was used to study the uniform distribution of ceramic reinforcing particles in the synthesized magnesium nanocomposites. ASTM standards were used to examine the mechanical properties of the intermixture. It was observed that the nano-MoO 3 ceramics were uniformly distributed within the matrix alloy, no residual porosity was observed, and the grain size of the intermixture was observed as 59.82 + /0.001 nm and due to enhanced grain refinement and interfacial reaction between the intermixtures, the mechanical properties of nanocomposites, such as tensile, compression, flexural and impact strengths, significantly increased over the as-cast magnesium alloy. The corrosion resistance was improved due to the reduced size of the Mg 17 Al 12 phase and the more uniform dissemination of ceramic strengthening particulates. Further, the improved load-bearing capacity and transfer layer enriched the wear resistance of magnesium alloy nanocomposites for all weight proportions. [Display omitted] • A vacuum-assisted stir casting technique created nano MoO 3 /AZ91D alloy composites. • Nano MoO 3 /AZ91D intermixture nucleates during solidification, exhibiting a refined grain structure. • The formation of intermetallic compounds improves the hardness of intermixtures. • Nano MoO 3 increases surface area with homogeneous stress distribution, decreasing localized damage. [ABSTRACT FROM AUTHOR]

Over the last few years, electroanalysis has made significant advancements, particularly in developing electrochemical sensors. Electrochemical sensors generally include emerging Photoelectrochemical and Electrochemiluminescence sensors, which combine optical techniques and traditional electrochemical bio/non-biosensors. Numerous EC-detecting methods have also been designed for commercial applications to detect biological and non-biological markers for various diseases. Analytical applications have recently focused significantly on one of the novel nanomaterials, the MXene. This material is being extensively investigated for applications in electrochemical sensors due to its unique mechanical, electronic, optical, active functional groups and thermal characteristics. This study extensively discusses the salient features of MXene-based electrochemical sensors, photoelectrochemical sensors, enzyme-based biosensors, immunosensors, aptasensors, electrochemiluminescence sensors, and electrochemical non-biosensors. In addition, their performance in detecting various substances and contaminants is thoroughly discussed. Furthermore, the challenges and prospects the MXene-based electrochemical sensors are elaborated. • MXene based enzymatic biosensors and non-enzymatic biosensor sensing capacity have been discussed in detailed. • MXene chemical and physical synthesizing routes have been reviewed. • Pristine MXene have low sensing capacity as compare to the Mxene that have composite with other distinct material. • MXene characteristics that favor the electrochemical performance of MXene have been presented. [ABSTRACT FROM AUTHOR]

In the present work, the synthesis of cellulose nanowhiskers (CNW)/chitosan nanocomposite films via deep eutectic solvents (DES) changing the chemical structures were carried out. It was observed that a pure chitosan film has broadband at 3180-3400 cm−1, indicating amide and hydroxyl groups. Upon CNW incorporation, the peak gets sharper and stronger and shifts to a greater wavelength. Further, the addition of DES infuses more elements of amide into the nanocomposite films. Moreover, the mechanical properties incorporating CNW filler into a chitosan matrix show an enhancement in tensile strength (TS), Young's modulus (YM), and elongation at break. The TS and YM increase while the elongation decrease as the CNW concentration increases. The YM of biocomposite films is increased to 723 MPa at 25% CNW into chitosan films. Besides, the TS has enhanced to 11.48 MPa at 15% CNW concentration in the biocomposite films. The elongation at break has decreased to 11.7% at 25% CNW concentration. Hence, incorporating CNW into the chitosan matrix via DES can still improve the mechanical properties of the nanocomposite films. Therefore, the application of DES results in a lower YM and TS as the films are hygroscopic. In conclusion, DES can be considered the new green solvent media for synthesizing materials. It has the potential to replace ionic liquids due to its biodegradability and non-toxic properties while preserving the character of low-vapour pressure. Besides that, chitosan can be used as potential material for applications in process industries, such as the biomedical and pharmaceutical industries. Thus, DES can be used as a green solvent and aim to reduce the toxic effect of chemicals on the environment during chemical production. • Application of DES attribute to the amide group in the synthesis of chitosan/CNW nanocomposite films. • The addition of CNW as reinforcing filler improves the mechanical properties of the chitosan matrix. • Thermal stability of nanocomposite films is improved by adding CNW as filler. • The addition of CNW in the chitosan matrix does not affect the glass transition temperature of nanocomposite films. [ABSTRACT FROM AUTHOR]

MXenes are an innovative class of 2D nanostructured materials gaining popularity for various uses in medicine, chemistry, and the environment. A larger outer layer area, exceptional stability and conductivity of heat, high porosity, and environmental friendliness are all characteristics of MXenes and their composites. As a result, MXenes have been used to produce Li-ion batteries, semiconductors, water desalination membranes, and hydrogen storage. MXenes have recently been used in many environmental remediations, frequently surpassing conventional materials, to treat groundwater contamination, surface waters, industrial and municipal wastewaters, and desalination. Due to their outstanding structural characteristics and the enormous specific surface area, they are widely utilized as adsorbents or membrane materials for the desalination of seawater. When used for electrochemical applications, MXene-composites can deionize via Faradaic capacitive deionization (CDI) and adsorb various organic and inorganic pollutants to treat the water. In general, as compared to other 2D nanomaterials, MXene has superb characteristics; because of their magnificent characteristics and they exhibit strong desalination capability. The current review paper discusses the desalination capability of MXenes and their composites. Focusing on the desalination capacity of MXene-based nanomaterials, this study discusses the characteristics and synthesis techniques of MXenes their composites along with their ion-rejection capability and pervaporation desalination of water via MXene-based membranes, capacitive deionization capability, solar desalination capability. Furthermore, the challenges and prospects of MXenes and their composites are highlighted. [Display omitted] • MXenes and MXene-based nanomaterials for desalinating salty water have been reviewed. • Extensive investigation on the characteristics of MXene has been presented. • The ability of MXenes to regenerate and their processes for removing salt are evaluated. • MXene-based material for desalination and future challenges was discussed. [ABSTRACT FROM AUTHOR]

Multiple ecological contaminants in gaseous, liquid, and solid forms are vented into ecosystems due to the huge growth of industrialization, which is today at the forefront of worldwide attention. High-efficiency removal of these environmental pollutants is a must because of the potential harm to public health and biodiversity. The alarming concern has led to the synthesis of improved nanomaterials for removing pollutants. A path to innovative methods for identifying and preventing several obnoxious, hazardous contaminants from entering the environment is grabbing attention. Various applications in diverse industries are seen as a potential directions for researchers. MXene is a new, excellent, and advanced material that has received greater importance related to the environmental application. Due to its unique physicochemical and mechanical properties, high specific surface area, physiological compatibility, strong electrodynamics, and raised specific surface area wettability, its applications are growing. This review paper examines the most recent methods and trends for environmental pollutant removal using advanced 2D Mxene materials. In addition, the history and the development of MXene synthesis were elaborated. Furthermore, an extreme summary of various environmental pollutants removal has been discussed, and the future challenges along with their future perspectives have been illustrated. [Display omitted] • The most crucial aspects of MXene materials are covered in the present studies. • MXenes with lots of terminal functional groups perform well. • The most recent developments in MXene materials technique are also covered in this review. • The characteristics of MXene material are also a focus of current research. • Application of Mxene materials for environmental remediation. [ABSTRACT FROM AUTHOR]

The use of renewable materials in the epoxidation reaction has gained increasing attention due to the need to reduce reliance on non-renewable resources and minimize environmental impact. To date, there is a paucity of studies on the optimization of process to produce epoxidized oleic acid by auto-catalyst epoxidation using formic acid (by product) as catalyst as it is not fully utilised. The aim of this study is to investigate the effect of hydrogen peroxide concentration, type of oxygen carrier and stirring speed on the auto catalyst epoxidation of oleic acid. In this study, auto-catalyzed epoxidation using formic acid was applied in which formic acid acts as both a reactant and a catalyst to produce oxirane. The maximum selectivity of oleic acid into oxirane was 58% by applying the optimum epoxidation reaction parameters. Based on the Fourier transform infrared (FTIR) spectrum, the absorption peak at 1100 cm−1 indicated the presence of oxirane rings (C–O–C bonds). Lastly, a mathematical model was developed using MATLAB software. In this model, the fourth-order Runge–Kutta method was integrated with genetic algorithm optimization to determine the kinetic model that fit with the experimental data. The kinetic model was validated by the fact that there was good agreement between the simulation and experimental data. [ABSTRACT FROM AUTHOR]

Water consumption has grown in recent years due to rising urbanization and industry. As a result, global water stocks are steadily depleting. As a result, it is critical to seek strategies for removing harmful elements from wastewater once it has been cleaned. In recent years, many studies have been conducted to develop new materials and innovative pathways for water purification and environmental remediation. Due to low energy consumption, low operating cost, and integrated facilities, membrane separation has gained significant attention as a potential technique for water treatment. In these directions, MXene which is the advanced 2D material has been explored and many applications were reported. However, research on MXene-based membranes is still in its early stages and reported applications are scatter. This review provides a broad overview of MXenes and their perspectives, including their synthesis, surface chemistry, interlayer tuning, membrane construction, and uses for water purification. Application of MXene based membrane for extracting pollutants such as heavy metals, organic contaminants, and radionuclides from the aqueous water bodies were briefly discussed. Furthermore, the performance of MXene-based separation membranes is compared to that of other nano-based membranes, and outcomes are very promising. In order to shed more light on the advancement of MXene-based membranes and their operational separation applications, significant advances in the fabrication of MXene-based membranes is also encapsulated. Finally, future prospects of MXene-based materials for diverse applications were discussed. [Display omitted] • Structure of MXene is briefly presented. • A comprehensive elaboration of synthesis of MXene and preparation of MXene-based membrane. • Properties of MXene and effect of properties on the performance of MXene, along with a comparison with other nanomembranes. • Removal of organic pollutants, heavy metals, and radionuclides from water by MXene. • Current challenges and future scope of MXene in the purification of water. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mxenes-based materials are excellent candidates for phase change material application. • MXene-based solar thermal energy storage applications have been highlighted. • Mxenes-based materials for Photovoltaic PCM has been elaborated. • Brief review of organic and ionic liquid based PCM was narrated. MXene is a new and excellent class of two-dimensional (2D) materials discovered in the last decade. The community of MXenes has drawn significant research attention because of its varied chemical structure and outstanding physicochemical characteristics in various fields, including thermal energy storage and environmental remediation applications. In the field of Material science, traditional material used in thermal energy storage devices exhibits several disadvantages, such as low thermal conductivity, reusability, cycling life and thermal storage capability. Therefore, the advanced 2D material MXene, because of various excellent characteristics, is extensively used in thermal energy storage applications. To capture thermal energy for effective use, convert solar energy to electrical or thermal energy, and store waste heat for a specific use, phase change material (PCM) may be used as a latent heat storage system. High-performance composite PCM has recently seen significant development as advanced energy storage materials. The phase change materials are extensively utilized as latent heat storage systems. PCM enables the storage of solar passive and other radiant heat as latent heat within a particular temperature, resulting in lower energy consumption, increased thermal comfort by trying to smooth out temperature changes during the day, and a decrease and shift in peak loads. Paraffin generally has a thermal conductivity in the ranges of 0.15–0.2 W/mK. It increases to 56.8 % by doping silicon nitride (Si 3 N 4) on the surface of organic phase change material paraffin. This study presents the most up-to-date, comprehensive, and trustworthy information on the role of MXene-based PCM in thermal energy storage applications. This review paper focuses on the thermal energy storage applications of 2D PCM. The thermal energy storage applications included Photovoltaic PCM, Solar water heater systems, Solar greenhouses, thermal Buildings, Cold storage, and air conditioning and refrigeration, respectively. In addition, an extensive summary of synthesis approaches of 2D materials and the effect of coating/incorporating substance loading on their performance was narrated. Furthermore, a brief review of organic, inorganic and ionic liquid based PCM was elaborated. Finally, future challenges and prospects for PCM were presented before the conclusion. Finally, this comprehensive review is helpful for the advancement and application of MXenes in thermal energy storage applications. [ABSTRACT FROM AUTHOR]

Multiwall carbon nanotubes (MWCNTs) were synthesized using a tubular microwave chemical vapor deposition technique, using acetylene and hydrogen as the precursor gases and ferrocene as catalyst. The novel MWCNT samples were tested for their performance in terms of Pb(II) binding. The synthesized MWCNT samples were characterized using Fourier Transform Infrared (FT-IR), Brunauer, Emmett and Teller (BET), Field Emission Scanning Electron Microscopy (FESEM) analysis, and the adsorption of Pb(II) was studied as a function of pH, initial Pb(II) concentration, MWCNT dosage, agitation speed, and adsorption time, and process parameters were optimized. The adsorption data followed both Freundlich and Langmuir isotherms. On the basis of the Langmuir model, Q max was calculated to be 104.2 mg/g for the microwave-synthesized MWCNTs. In order to investigate the dynamic behavior of MWCNTs as an adsorbent, the kinetic data were modeled using pseudo first-order and pseudo second-order equations. Different thermodynamic parameters, viz. , ∆ H 0 , ∆ S 0 and ∆ G 0 were evaluated and it was found that the adsorption was feasible, spontaneous and endothermic in nature. The statistical analysis revealed that the optimum conditions for the highest removal (99.9%) of Pb(II) are at pH 5, MWCNT dosage 0.1 g, agitation speed 160 r/min and time of 22.5 min with the initial concentration of 10 mg/L. Our results proved that microwave-synthesized MWCNTs can be used as an effective Pb(II) adsorbent due to their high adsorption capacity as well as the short adsorption time needed to achieve equilibrium. [ABSTRACT FROM AUTHOR]

The presence of metal with microwave irradiation has always invited controversial arguments as the metal will catch on fire easily. But interestingly, researchers found that arc discharge phenomena provide a promising way for molecule cracking to synthesize nanomaterials. This study developed a single-step yet affordable synthesis approach that combines microwave heating and arcing in transforming crude palm oil into magnetic nanocarbon (MNC), which can be considered a new alternative for the palm oil sectors. It involves synthesizing the medium at a partial inert condition with constant coiled stainless steel metal wire (dielectric media) and ferrocene (catalyst). This approach successfully demonstrates heating at a temperature ranging from 190.9 to 472.0 °C with different synthesis times (10–20 min). The produced MNC shows formations of spheres with average sizes of 20.38–31.04 nm, mesoporous structure (SBET: 14.83–151.95 m2/g), and high content of fixed carbon (52.79–71.24wt%), and the ratio of the D and G bands (ID/IG) is 0.98–0.99. The formation of new peaks in the FTIR spectra (522.29–588.48 cm−1) supports the appearance of the FeO compounds from the ferrocene. The magnetometer shows high magnetization saturation (22.32–26.84 emu/g) in ferromagnetic materials. The application of the MNC in wastewater treatment has been demonstrated by evaluating their adsorbent capability with Methylene Blue (MB) adsorption test at a different concentrations varying between 5 and 20 ppm. The MNC produced at synthesis time (20 min) shows the highest adsorption efficiency (10.36 mg/g) compared to others, with 87.79% removal of MB dye. As a result, the value for Langmuir is not promising compared to Freundlich, with R2 being around 0.80, 0.98, and 0.99 for MNC synthesized at 10 min (MNC10), 15 min (MNC15), and 20 min (MNC20), respectively. Hence, the adsorption system is in a heterogeneous condition. The microwave-assisted arcing thereby presents a promising approach to transforming CPO into MNC that could remove the hazardous dye. [ABSTRACT FROM AUTHOR]

Industrial effluents contain several organic and inorganic contaminants. Among others, dyes and heavy metals introduce a serious threat to drinking waterbodies. These pollutants can be noxious or carcinogenic in nature, and harmful to humans and different aquatic species. Therefore, it is of high importance to remove heavy metals and dyes to reduce their environmental toxicity. This has led to an extensive research for the development of novel materials and techniques for the removal of heavy metals and dyes. One route to the removal of these pollutants is the utilization of magnetic carbon nanotubes (CNT) as adsorbents. Magnetic carbon nanotubes hold remarkable properties such as surface-volume ratio, higher surface area, convenient separation methods, etc. The suitable characteristics of magnetic carbon nanotubes have led them to an extensive search for their utilization in water purification. Along with magnetic carbon nanotubes, the buckypaper (BP) membranes are also favorable due to their unique strength, high porosity, and adsorption capability. However, BP membranes are mostly used for salt removal from the aqueous phase and limited literature shows their applications for removal of heavy metals and dyes. This study focuses on the existence of heavy metal ions and dyes in the aquatic environment, and methods for their removal. Various fabrication approaches for the development of magnetic-CNTs and CNT-based BP membranes are also discussed. With the remarkable separation performance and ultra-high-water flux, magnetic-CNTs, and CNT-based BP membranes have a great potential to be the leading technologies for water treatment in future. [Display omitted] • Existence and sources of heavy metals and dyes in different water-sources are discussed. • Removal of heavy metals and dyes by several approaches are reviewed. • Fabrication of magnetic-CNTs and CNT-based BP membranes are presented. • Magnetic-CNTs and CNT-based BP membranes for heavy metals and dyes removal are presented. • Future prospects and challenges of magnetic-CNTs and CNT-based BP membranes in water applications are highlighted. [ABSTRACT FROM AUTHOR]

Plastic waste is utilized aggressively for food, product packaging, cosmetics, toys, clothes, and even furniture. As a result, discarded plastic as a waste has grown uncontrollably worldwide, most of it ending up as landfill. With increasing concern, researchers have made efforts to convert this plastic waste into a more useful product. Along these lines, this study focuses on producing 10 tons of diesel per day through fast pyrolysis at 450 °C in the fluidized bed reactor for a feed rate of 3000 kg of plastic waste per hour. The production was simulated in Aspen HYSYS V11 to ensure the desired yield. Further, a detailed economic analysis is carried out to estimate the return on investment and total cost per year, as well as the payback period and the profit for different scenarios. [ABSTRACT FROM AUTHOR]

Plastic waste is being manufactured for the production of hydrogen. The amount of plastic waste collected annually is 189,953 tonnes from adjacent nations like Indonesia and Malaysia. Polyethylene (PE), Polypropylene (PP), Polyethylene Terephthalate (PET), Polyvinyl chloride (PVC), and Polystyrene (PS) are the five most prevalent forms of plastic found in most waste. Pyrolysis, water gas shift and steam reforming reaction, and pressure swing adsorption are the three main phases utilized and studied. In this research, authors examines the energy consumption on every stage. The plastic waste can be utilized to manufacture many hydrocarbons using the pyrolysis reaction. For this process, fast pyrolysis is being used at a temperature of 500 °C. A neutralization process is also needed due to the presence of Hydrochloric acid from the pyrolysis reaction, with the addition of sodium hydroxide. This is being carried to prevent any damage to the reactor during the process. Secondly, the steam reforming process continues after the water gas shift reaction has produced steam and carbon monoxide, followed by carbon dioxide and hydrogen formation. Lastly, pressure swing adsorption is designed to extract H2S and CO2 from the water gas shift and steam reforming reaction for greater purity of hydrogen. From the simulation study, it is observed that using various types of plastic waste procured (total input of 20,000 kg per hour of plastics) from, Brunei Darussalam, Malaysia and Indonesia, can produce about 340,000 tons of Hydrogen per year. Additionally, the annual profit of the Hydrogen production is estimated to be between $ 271,158,100 and $ 358,480,200. As per the economic analysis, it can be said that its a good to start hydrogen production plant in these regions. [ABSTRACT FROM AUTHOR]

A numerical analysis of a CdTe/Si dual-junction solar cell in terms of defect density introduced at various defect energy levels in the absorber layer is provided. The impact of defect concentration is analyzed against the thickness of the CdTe layer, and variation of the top and bottom cell bandgaps is studied. The results show that CdTe thin film with defects density between 1014 and 1015 cm−3 is acceptable for the top cell of the designed dual-junction solar cell. The variations of the defect concentrations against the thickness of the CdTe layer indicate that the open circuit voltage, short circuit current density, and efficiency (ƞ) are more affected by the defect density at higher CdTe thickness. In contrast, the Fill factor is mainly affected by the defect density, regardless of the thin film's thickness. An acceptable defect density of up to 1015 cm−3 at a CdTe thickness of 300 nm was obtained from this work. The bandgap variation shows optimal results for a CdTe with bandgaps ranging from 1.45 to 1.7 eV in tandem with a Si bandgap of about 1.1 eV. This study highlights the significance of tailoring defect density at different energy levels to realize viable CdTe/Si dual junction tandem solar cells. It also demonstrates how the impact of defect concentration changes with the thickness of the solar cell absorber layer. [ABSTRACT FROM AUTHOR]

This study synthesized a highly efficient KOH-treated sunflower stem activated carbon (KOH-SSAC) using a two-step pyrolysis process and chemical activation using KOH. The resulting material exhibited exceptional properties, such as a high specific surface area (452 m2/g) and excellent adsorption capacities for phenol (333.03 mg/g) and bisphenol A (BPA) (365.81 mg/g). The adsorption process was spontaneous and exothermic, benefiting from the synergistic effects of hydrogen bonding, electrostatic attraction, and stacking interactions. Comparative analysis also showed that KOH-SSAC performed approximately twice as well as sunflower stem biochar (SSB), indicating its potential for water treatment and pollutant removal applications. The study suggests the exploration of optimization strategies to further enhance the efficiency of KOH-SSAC in large-scale scenarios. These findings contribute to the development of improved materials for efficient water treatment and pollution control. [ABSTRACT FROM AUTHOR]

In this study, zeolite Y was synthesised using a novel method. The heat generated from the reaction of H2SO4 with metakaolin was used as a heat source instead of applying external heat for the dealuminated process. The synthesised zeolite Y produced was analysed by scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier-infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDS) and Brunauer–Emmett–Teller (BET). Zeolite Y synthesis was mesoporous because of its pore diameter (30.53 nm), as shown in the BET results. Surface area and pore size decrease after adsorption due to dye deposition on the adsorbent's surface. FTIR has bonds like O–H, C–H, –CH3, and –COOH responsible for adsorption. The maximum adsorption capacity of eosin yellow (EY) and methyl orange (MO) on to zeolite Y by the Langmuir isotherm was 52.91 mg/g and 20.62 mg/g respectively, at pH 2.5 and 8 for EY and MO dye. The batch adsorption studies were conducted, and the influence of different parameters (i.e., adsorbent dose, adsorption time, initial dye concentration, pH and temperature) was investigated. Experimental data were analysed by two linear model equations (Langmuir and Freundlich isotherms), and it was found that the Langmuir isotherm model best describes the adsorption data for methyl orange and Freundlich isotherm for eosin yellow, respectively. Adsorption rate constants were determined using linear pseudo-first-order and pseudo-second-order. The results showed that MO and EY dye adsorption onto zeolite Y followed a pseudo-second-order kinetic model. Thermodynamic studies show that adsorption was an exothermic reaction (enthalpy < 0) and feasible ( (G i b b s f r e e e n e r g y) < 0 ) at various temperatures under investigation. [ABSTRACT FROM AUTHOR]

Recently, most service or product-oriented industries have been focusing on their activities to uphold the green and sustainable environment protocol owing to the increased environmental pollution. Concerning this issue, industries are now concentrating on developing recyclable or waste materials products. This research advocates developing and validating a banana fiber sandwich composite to promote the beneficial usage of bio-waste. The composite sandwich specimens were fabricated with resin-impregnated woven banana fiber mat as a skin, and the core was reinforced with three different weight percentages (5, 7.5 and 10%) of chopped banana fiber. The sandwich specimens were pressed into a three-point bending test to validate the structural integrity. The flexural characteristics like flexural strength and modulus were examined experimentally, whereas the key strength indices like flexural stiffness and core shear modulus were evaluated analytically. Post-fracture surfaces were studied through a scanning electron microscope to investigate the failure mechanism. The experimental and analytical results indicate that 10% banana fiber content in the sandwich core increases the flexural strength and flexural modulus to 225% and 147%, respectively, compared to the neat epoxy core. The numerical simulation was also performed through FEA to validate the experimental findings. The numerical results are in good concurrence with the experimental one. [ABSTRACT FROM AUTHOR]

A comprehensive understanding of physiochemical properties, thermal degradation behavior and chemical composition is significant for biomass residues before their thermochemical conversion for energy production. In this investigation, teff straw (TS), coffee husk (CH), corn cob (CC), and sweet sorghum stalk (SSS) residues were characterized to assess their potential applications as value-added bioenergy and chemical products. The thermal degradation behavior of CC, CH, TS and SSS samples is calculated using four different heating rates. The activation energy values ranged from 81.919 to 262.238 and 85.737–212.349 kJ mol−1 and were generated by the KAS and FWO models and aided in understanding the biomass conversion process into bio-products. The cellulose, hemicellulose, and lignin contents of CC, CH, TS, and SSS were found to be in the ranges of 31.56–41.15%, 23.9–32.02%, and 19.85–25.07%, respectively. The calorific values of the residues ranged from 17.3 to 19.7 MJ/kg, comparable to crude biomass. Scanning electron micrographs revealed agglomerated, irregular, and rough textures, with parallel lines providing nutrient and water transport pathways in all biomass samples. Energy Dispersive X-ray spectra and X-ray diffraction analysis indicated the presence of high carbonaceous material and crystalline nature. FTIR analysis identified prominent band peaks at specific wave numbers. Based on these findings, it can be concluded that these residues hold potential as energy sources for various applications, such as the textile, plastics, paints, automobile, and food additive industries. [ABSTRACT FROM AUTHOR]

Toxic dyes in water bodies and bacterial pathogens pose serious global challenges to human health and the environment. Zinc oxide nanoparticles (ZnO NPs) demonstrate remarkable photocatalytic and antibacterial potency against reactive dyes and bacterial strains. In this work, PVP-ZnO NPs have been prepared via the co-precipitation method using polyvinylpyrrolidone (PVP) as a surfactant. The NPs' microstructure and morphology were studied using X-ray diffraction (XRD), having a size of 22.13 nm. High-resolution transmission electron microscope (HR-TEM) and field emission scanning electron microscopy (FESEM) analysis showed spherical-shaped PVP-ZnO NPs with sizer ranging from 20 to 30 nm. Fourier Transform Infrared Spectroscopy (FT-IR) confirmed the hybrid nature of the NPs, and UV–Vis spectroscopy showed an absorption peak at 367 nm. The PVP-ZnO NPs exhibited high photocatalytic activity, achieving 88% and nearly 95% degradation of reactive red-141 azo dye with 10 mg and 20 mg catalyst dosages, respectively. The antibacterial properties of the NPs were demonstrated against Escherichia coli and Bacillus subtilis, with inhibition zones of 24 mm and 20 mm, respectively. These findings suggest that PVP-ZnO NPs can be effectively used for water treatment, targeting both dye and pathogenic contaminants. [ABSTRACT FROM AUTHOR]

Discharging untreated dye-containing wastewater gives rise to environmental pollution. The present study investigated the removal efficiency and adsorption mechanism of Acid Red 18 (AR18) utilizing hexadecyl-trimethyl ammonium chloride (HDTMA.Cl) modified Nano-pumice (HMNP), which is a novel adsorbent for AR18 removal. The HDTMA.Cl is characterized by XRD, XRF, FESEM, TEM, BET and FTIR analysis. pH, contact time, initial concentration of dye and adsorbent dose were the four different parameters for investigating their effects on the adsorption process. Response surface methodology-central composite design was used to model and improve the study to reduce expenses and the number of experiments. According to the findings, at the ideal conditions (pH = 4.5, sorbent dosage = 2.375 g/l, AR18 concentration = 25 mg/l, and contact time = 70 min), the maximum removal effectiveness was 99%. The Langmuir (R2 = 0.996) and pseudo-second-order (R2 = 0.999) models were obeyed by the adsorption isotherm and kinetic, respectively. The nature of HMNP was discovered to be spontaneous, and thermodynamic investigations revealed that the AR18 adsorption process is endothermic. By tracking the adsorption capacity of the adsorbent for five cycles under ideal conditions, the reusability of HMNP was examined, which showed a reduction in HMNP's adsorption effectiveness from 99 to 85% after five consecutive recycles. [ABSTRACT FROM AUTHOR]

Recently, most service or product-oriented industries have been focusing on their activities to uphold the green and sustainable environment protocol owing to the increased environmental pollution. Concerning this issue, industries are now concentrating on developing recyclable or waste materials products. This research advocates developing and validating a banana fiber sandwich composite to promote the beneficial usage of bio-waste. The composite sandwich specimens were fabricated with resin-impregnated woven banana fiber mat as a skin, and the core was reinforced with three different weight percentages (5, 7.5 and 10%) of chopped banana fiber. The sandwich specimens were pressed into a three-point bending test to validate the structural integrity. The flexural characteristics like flexural strength and modulus were examined experimentally, whereas the key strength indices like flexural stiffness and core shear modulus were evaluated analytically. Post-fracture surfaces were studied through a scanning electron microscope to investigate the failure mechanism. The experimental and analytical results indicate that 10% banana fiber content in the sandwich core increases the flexural strength and flexural modulus to 225% and 147%, respectively, compared to the neat epoxy core. The numerical simulation was also performed through FEA to validate the experimental findings. The numerical results are in good concurrence with the experimental one. [ABSTRACT FROM AUTHOR]

A comprehensive understanding of physiochemical properties, thermal degradation behavior and chemical composition is significant for biomass residues before their thermochemical conversion for energy production. In this investigation, teff straw (TS), coffee husk (CH), corn cob (CC), and sweet sorghum stalk (SSS) residues were characterized to assess their potential applications as value-added bioenergy and chemical products. The thermal degradation behavior of CC, CH, TS and SSS samples is calculated using four different heating rates. The activation energy values ranged from 81.919 to 262.238 and 85.737–212.349 kJ mol−1 and were generated by the KAS and FWO models and aided in understanding the biomass conversion process into bio-products. The cellulose, hemicellulose, and lignin contents of CC, CH, TS, and SSS were found to be in the ranges of 31.56–41.15%, 23.9–32.02%, and 19.85–25.07%, respectively. The calorific values of the residues ranged from 17.3 to 19.7 MJ/kg, comparable to crude biomass. Scanning electron micrographs revealed agglomerated, irregular, and rough textures, with parallel lines providing nutrient and water transport pathways in all biomass samples. Energy Dispersive X-ray spectra and X-ray diffraction analysis indicated the presence of high carbonaceous material and crystalline nature. FTIR analysis identified prominent band peaks at specific wave numbers. Based on these findings, it can be concluded that these residues hold potential as energy sources for various applications, such as the textile, plastics, paints, automobile, and food additive industries. [ABSTRACT FROM AUTHOR]

Toxic dyes in water bodies and bacterial pathogens pose serious global challenges to human health and the environment. Zinc oxide nanoparticles (ZnO NPs) demonstrate remarkable photocatalytic and antibacterial potency against reactive dyes and bacterial strains. In this work, PVP-ZnO NPs have been prepared via the co-precipitation method using polyvinylpyrrolidone (PVP) as a surfactant. The NPs' microstructure and morphology were studied using X-ray diffraction (XRD), having a size of 22.13 nm. High-resolution transmission electron microscope (HR-TEM) and field emission scanning electron microscopy (FESEM) analysis showed spherical-shaped PVP-ZnO NPs with sizer ranging from 20 to 30 nm. Fourier Transform Infrared Spectroscopy (FT-IR) confirmed the hybrid nature of the NPs, and UV–Vis spectroscopy showed an absorption peak at 367 nm. The PVP-ZnO NPs exhibited high photocatalytic activity, achieving 88% and nearly 95% degradation of reactive red-141 azo dye with 10 mg and 20 mg catalyst dosages, respectively. The antibacterial properties of the NPs were demonstrated against Escherichia coli and Bacillus subtilis, with inhibition zones of 24 mm and 20 mm, respectively. These findings suggest that PVP-ZnO NPs can be effectively used for water treatment, targeting both dye and pathogenic contaminants. [ABSTRACT FROM AUTHOR]

Discharging untreated dye-containing wastewater gives rise to environmental pollution. The present study investigated the removal efficiency and adsorption mechanism of Acid Red 18 (AR18) utilizing hexadecyl-trimethyl ammonium chloride (HDTMA.Cl) modified Nano-pumice (HMNP), which is a novel adsorbent for AR18 removal. The HDTMA.Cl is characterized by XRD, XRF, FESEM, TEM, BET and FTIR analysis. pH, contact time, initial concentration of dye and adsorbent dose were the four different parameters for investigating their effects on the adsorption process. Response surface methodology-central composite design was used to model and improve the study to reduce expenses and the number of experiments. According to the findings, at the ideal conditions (pH = 4.5, sorbent dosage = 2.375 g/l, AR18 concentration = 25 mg/l, and contact time = 70 min), the maximum removal effectiveness was 99%. The Langmuir (R2 = 0.996) and pseudo-second-order (R2 = 0.999) models were obeyed by the adsorption isotherm and kinetic, respectively. The nature of HMNP was discovered to be spontaneous, and thermodynamic investigations revealed that the AR18 adsorption process is endothermic. By tracking the adsorption capacity of the adsorbent for five cycles under ideal conditions, the reusability of HMNP was examined, which showed a reduction in HMNP's adsorption effectiveness from 99 to 85% after five consecutive recycles. [ABSTRACT FROM AUTHOR]

Abstract Over the past few decades, enormous interest has been manifested in utilizing biomass or agricultural wastes as a renewable resource for energy and advanced material production. Despite being the utmost abundant polymer on earth, nanocellulose has drawn tremendous attention due to its intrinsic reliability and sustainability. In this study, nanocrystalline cellulose (NCC) was isolated from oil palm biomass waste i.e. oil palm empty fruit bunch (EFB) via a multistep process to testify its high capacity as a biosorbent for textile effluent contaminant remediation. Fourier transform infrared spectroscopy (FTIR) suggested that lignin, hemicellulose and other impurities had been effectively removed at different stages of preparation which was generally in agreement with ASTM chemical composition analysis. Thermogravimetric analysis with derivative thermograms (TGA-DTG) observed the extracted NCC to have the lowest weight loss throughout water evaporation region (25 °C - 100 °C), cellulose thermal degradation region (150 °C - 380 °C) and carbonic residue degradation (up to 600 °C) owing to its compact crystalline structure as evidenced from X-ray diffraction (XRD) analysis. Batch adsorption were conducted to study effect of contact time (up to 200 min), adsorbent dosage (0.005–0.05 g), pH (2–10), agitation (50–250 rpm) and adsorbate concentration (50–300 mg/L) at 30 ± 2 °C. Field emission scanning electron microscope (FESEM) observed a flower-like structure of methylene blue (MB) coating upon adsorption, following a type II adsorption isotherm which suggest an adsorption occurred on mesoporous structure. The kinetic data agreed well with pseudo-second-order model which implied the current study a chemisorption process. As adsorption capacity was highly dependent on adsorbate concentration and adsorbent dosage, 50.91 mg/g was recorded for MB solution (50 mg/L) at adsorbent dosage as low as 0.066 mg/ml; a very encouraging outcome in the recent years of cellulosic research suggesting NCC a highly promising candidate for uprising functional cellulosic soft material fabrication. Graphical abstract Image 1 Highlights • Nanocellulose with high cellulose I content and crystallinity was developed from oil palm EFB. • Characterization was made via ASTM composition analysis, FTIR, TGA-DTG, XRD, BET and FESEM technique. • Adsorption best fitted to pseudo-second-order kinetic and Langmuir isotherm model. • Electron microscope observed flower-like structure of MB dye coating upon adsorption. [ABSTRACT FROM AUTHOR]

A typical ferrite/martensitic heat-resistant steel (T91) is widely used in reheaters, superheaters and power stations. Cr3C2-NiCr-based composite coatings are known for wear-resistant coatings at elevated temperature applications. The current work compares the microstructural studies of 75 wt% Cr3C2- 25 wt% NiCr-based composite clads developed through laser and microwave energy on a T91 steel substrate. The developed clads of both processes were characterized through a field emission scanning electron microscope (FE-SEM) attached with energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and assessment of Vickers microhardness. The Cr3C2-NiCr based clads of both processes revealed better metallurgical bonding with the chosen substrate. The microstructure of the developed laser clad shows a distinctive dense solidified structure, with a rich Ni phase occupying interdendritic spaces. In the case of microwave clad, the hard chromium carbide particles consistently dispersed within the soft nickel matrix. EDS study evidenced that the cell boundaries are lined with chromium where Fe and Ni were found inside the cells. The X-ray phase analysis of both the processes evidenced the common presence of phases like chromium carbides (Cr7C3, Cr3C2, Cr23C6), Iron Nickel (FeNi3) and chromium-nickel (Cr3Ni2, CrNi), despite these phases iron carbides (Fe7C3) are observed in the developed microwave clads. The homogeneous distributions of such carbides in the developed clad structure of both processes indicated higher hardness. The typical microhardness of the laser-clad (1142 ± 65HV) was about 22% higher than the microwave clad (940 ± 42 HV). Using a ball-on-plate test, the study analyzed microwave and laser-clad samples' wear behavior. Laser-cladding samples showed superior wear resistance due to hard carbide elements. At the same time, microwave-clad samples experienced more surface damage and material loss due to micro-cutting, loosening, and fatigue-induced fracture. [ABSTRACT FROM AUTHOR]

Ionogels are hybrid materials comprising an ionic liquid confined within a polymer matrix. They have garnered significant interest due to their unique properties, such as high ionic conductivity, mechanical stability, and wide electrochemical stability. These properties make ionogels suitable for various applications, including energy storage devices, sensors, and solar cells. However, optimizing the electrochemical performance of ionogels remains a challenge, as the relationship between specific capacitance, ionic conductivity, and electrolyte solution concentration is yet to be fully understood. In this study, we investigate the impact of electrolyte solution concentration on the electrochemical properties of ionogels to identify the correlation for enhanced performance. Our findings demonstrate a clear relationship between the specific capacitance and ionic conductivity of ionogels, which depends on the availability of mobile ions. The reduced number of ions at low electrolyte solution concentrations leads to decreased ionic conductivity and specific capacitance due to the scarcity of a double layer, constraining charge storage capacity. However, at a 31 vol% electrolyte solution concentration, an ample quantity of ions becomes accessible, resulting in increased ionic conductivity and specific capacitance, reaching maximum values of 58 ± 1.48 μS/cm and 45.74 F/g, respectively. Furthermore, the synthesized ionogel demonstrates a wide electrochemical stability of 3.5 V, enabling diverse practical applications. This study provides valuable insights into determining the optimal electrolyte solution concentration for enhancing ionogel electrochemical performance for energy applications. It highlights the impact of ion pairs and aggregates on ion mobility within ionogels, subsequently affecting their resultant electrochemical properties. [ABSTRACT FROM AUTHOR]

A limited experimental work was on multi-walled carbon nanotube (MWCNT)—water nanofluid with surfactant in the solar parabolic collector at low volume concentrations. At high-volume concentrated nanofluid, the pressure drop was more due to an increase in the viscosity of the working fluid and an increase in the nanoparticle cost; hence it is not economical. This report attempted to use Sodium Dodecyl Benzene Sulfonate (SDBS) surfactant in the low-volume concentrated MWCNT-water nanofluid to establish effective heat transfer in solar parabolic collector applications. The stable MWCNT-water nanofluid was prepared at 0.0158, 0.0238, and 0.0317 volume concentrations. The experiments were conducted from 10:00 to 16:00 at 6, 6.5 and 7 L/min flow rates concerning ASHRAE Standards. At the 7 L/min flow rate of the working fluid, having a minimum temperature difference between the working fluid and absorber tube leads to better heat transfer. The increased volume concentration of MWCNT in the water enhances the surface area interaction between water and MWCNT nanoparticles. This results in maximum solar parabolic collector efficiency at 0.0317 vol% with a 7 L/min flow rate and 10–11% higher than the distilled water. [ABSTRACT FROM AUTHOR]

MXene is a magical class of 2D nanomaterials and emerging in many applications in diverse fields. Due to the multiple advantageous characteristics of its fundamental components, such as structural, physicochemical, optical, and occasionally even biological characteristics. However, it is limited in the biomedical industry due to poor physiological stability, decomposition rate, and lack of controlled and sustained drug release. These limitations can be overcome when MXene forms composites with other 2D materials. The efficiency of pure MXene in biomedicine is inferior to that of MXene-based composites. The availability of functionality on the exterior part of MXene has a key role in the modification of their surface and their characteristics. This review provides an extensive discussion on the synthesizing of MXene and the role of the surface functionalities on the efficiency of MXene. In addition, a detailed discussion of the biomedical applications of MXene, including antibacterial activity, regenerative medicine, CT scan capability, drug delivery, diagnostics, MRI and biosensing capability. Furthermore, an outline of the future problems and challenges of MXene-based materials for biomedical applications was narrated. Thus, these salient features showcase the potential of MXene-based material and will be a breakthrough in biomedical applications in the near future. • MXenes-based materials are excellent candidates for biomedical applications. • MXene has superior biomedical performance as compared to other 2D materials. • MXene-based materials for effective coating for biomedical application was narrated. • The impact of synthesizing techniques on the Surface functionalities of MXene has been addressed. [ABSTRACT FROM AUTHOR]

Several 2D nanomaterials are available for the adsorption of various contaminants. However, MXene-based 2D nano-adsorbents possess many fascinating characteristics compared to the traditional 2D nano-adsorbents. The properties include excellent thermochemical stability, large specific surface area, large thermal and electrical conductivity, and many active sites, very high active functional groups, superb adsorption/reduction capability. These outstanding properties make MXene-based adsorbents attractive for the adsorption of various pollutants from wastewater. They are widely used for the adsorption of harmful contaminants with effective removal power, suitable adsorption capacity and selectivity. The number of thermophysical key factors are water quality, adsorbent quantity/amount, pH, adsorption time, and the valuable impact of adsorption temperature on the elimination efficiency of MXene-based adsorbents. This review extensively compares various synthesizing techniques of MXene and MXene-based membranes, and their superb characteristics of MXene are discussed thoroughly. In addition, it provides extensive, advanced, and the latest reliable data results on the removal of various contaminants via MXene-based adsorbent, including radioactive, organic and inorganic pollutants, compared to the previously published articles. Furthermore, the difficulties and directions for upcoming research are presented. Overall, the most recent research findings for a trustworthy understanding of MXene behaviour as adsorbents are narrated. [Display omitted] • The efficiency of Ti3C2Tx adsorbent for micropollutant removal was narrated. • The underlying mechanism Ti3C2Tx's outstanding adsorption efficiency is explained. • MXene-based adsorbent synthesizing methods are discussed. • MXene-based adsorbents possessed the highest adsorption capacity [ABSTRACT FROM AUTHOR]

To date, the development of renewable fuels has become a normal phenomenon to solve the problem of diesel fuel emissions and the scarcity of fossil fuels. Biodiesel production has some limitations, such as two-step processes requiring high free fatty acids (FFAs), oil feedstocks and gum formation. Hydrotreated vegetable oil (HVO) is a newly developed international renewable diesel that uses renewable feedstocks via the hydrotreatment process. Unlike FAME, FFAs percentage doesn't affect the HVO production and sustains a higher yield. The improved characteristics of HVO, such as a higher cetane value, better cold flow properties, lower emissions and excellent oxidation stability for storage, stand out from FAME biodiesel. Moreover, HVO is a hydrocarbon without oxygen content, but FAME is an ester with 11% oxygen content which makes it differ in oxidation stability. Waste sludge palm oil (SPO), an abundant non-edible industrial waste, was reused and selected as the feedstock for HVO production. Techno-economical and energy analyses were conducted for HVO production using Aspen HYSYS with a plant capacity of 25,000 kg/h. Alternatively, hydrogen has been recycled to reduce the hydrogen feed. With a capital investment of RM 65.86 million and an annual production cost of RM 332.56 million, the base case of the SPO-HVO production process was more desirable after consideration of all economic indicators and HVO purity. The base case of SPO-HVO production could achieve a return on investment (ROI) of 89.03% with a payback period (PBP) of 1.68 years. The SPO-HVO production in this study has observed a reduction in the primary greenhouse gas, carbon dioxide (CO 2) emission by up to 90% and the total annual production cost by nearly RM 450 million. Therefore, SPO-HVO production is a potential and alternative process to produce biobased diesel fuels with waste oil. • Waste palm oil is produced using a sustainable hydrotreated vegetable oil production technology. • Techno-economic and energy analysis was based on 25,000 kg/h plant capacity. • Cheap feedstock and sustainable process for hydrotreated vegetable oil production. • The case study demonstrated that recycling hydrogen is preferred for economic viability. [ABSTRACT FROM AUTHOR]

Contamination of water resources by industrial effluents containing heavy metal ions and management of solid waste from agricultural and food industries is a serious issue. This study presents the valorization of waste walnut shells as an effective and environment-friendly biosorbent for sequestrating Cr(VI) from aqueous media. The native walnut shell powder (NWP) was chemically modified with alkali (AWP) and citric acid (CWP) to obtain modified biosorbents with abundant availability of pores as active centers, as confirmed by BET analysis. During batch adsorption studies, the process parameters for Cr(VI) adsorption were optimized at pH 2.0. The adsorption data were fitted to isotherm and kinetic models to compute various adsorption parameters. The adsorption pattern of Cr(VI) was well explained by the Langmuir model suggesting the adsorbate monolayer formation on the surface of the biosorbents. The maximum adsorption capacity, qm, for Cr(VI) was achieved for CWP (75.26 mg/g), followed by AWP (69.56 mg/g) and NWP (64.82 mg/g). Treatment with sodium hydroxide and citric acid improved the adsorption efficiency of the biosorbent by 4.5 and 8.2%, respectively. The endothermic and spontaneous adsorption was observed to trail the pseudo-second-order kinetics under optimized process parameters. Thus, the chemically modified walnut shell powder can be an eco-friendly adsorbent for Cr(VI) from aqueous solutions. [ABSTRACT FROM AUTHOR]

A reliable and accurate diagnosis and identification system is required to prevent and manage tea leaf diseases. Tea leaf diseases are detected manually, increasing time and affecting yield quality and productivity. This study aims to present an artificial intelligence-based solution to the problem of tea leaf disease detection by training the fastest single-stage object detection model, YOLOv7, on the diseased tea leaf dataset collected from four prominent tea gardens in Bangladesh. 4000 digital images of five types of leaf diseases are collected from these tea gardens, generating a manually annotated, data-augmented leaf disease image dataset. This study incorporates data augmentation approaches to solve the issue of insufficient sample sizes. The detection and identification results for the YOLOv7 approach are validated by prominent statistical metrics like detection accuracy, precision, recall, mAP value, and F1-score, which resulted in 97.3%, 96.7%, 96.4%, 98.2%, and 0.965, respectively. Experimental results demonstrate that YOLOv7 for tea leaf diseases in natural scene images is superior to existing target detection and identification networks, including CNN, Deep CNN, DNN, AX-Retina Net, improved DCNN, YOLOv5, and Multi-objective image segmentation. Hence, this study is expected to minimize the workload of entomologists and aid in the rapid identification and detection of tea leaf diseases, thus minimizing economic losses. [ABSTRACT FROM AUTHOR]

Adsorption is most commonly applied in water treatment, gas purification/separation, catalysis, etc. It is a very simple and inexpensive technique. However, the performance depends on the type of adsorbent and its dosage. Researchers across the world keep seeking low-cost and more effective adsorbents. As a result, millions of research publications on adsorption have been published yearly. Most of these publications report the synthesis of new adsorbents from various sources and their application in the remediation of several inorganic and organic pollutants from water bodies. Researchers attempt to fit their experimental results with various isotherm models to understand the adsorption mechanism. Some researchers fit data into linear isotherm models, while others add non-linear isotherm models for estimating the isotherm parameters. The fit of isotherm models differs for various adsorbents and contaminants. The present paper is comprehensive review compiling information on isotherm models that explain the intrinsic mechanisms of adsorptive removal of pollutants such as antibiotics, dyes, proteins, pesticides and heavy metal ions. Furthermore, a detailed characteristic property of numerous cationic dyes, anionic dyes, proteins, antibiotics, pesticides and heavy metal ions was also discussed. It is observed that based on the literature reviewed, it was found that the adsorption equilibrium data of cationic dyes and anionic dyes were well defined with the Langmuir model. Additionally, in the case of the adsorption of proteins, antibiotics and heavy metal ions, the Langmuir model is well matched among all applications. [ABSTRACT FROM AUTHOR]

Although the in vivo toxicity of nanoplastics (NPs) has already been reported in different model systems, their effects on mammalian behavior are poorly understood. Thus, we aimed to evaluate whether exposure to polystyrene (PS) NPs (diameter: 23.03 ± 0.266 nm) alters the behavior (locomotor, anxiety-like and antipredator) of male Swiss mice, induces brain antioxidant activity, and erythrocyte DNA damage. For this, the animals were exposed to NPs for 20 days at different doses (6.5 ng/kg and 6500 ng/kg). Initially, we did not observe any effect of pollutants on the locomotor activity of the animals (inferred via open field test and Basso mouse scale for locomotion). However, we noticed an anxiolytic-like behavior (in the open field test) and alterations in the antipredatory defensive response of mice exposed to PS NPs, when confronted with their predator potential (snake, Pantherophis guttatus). Furthermore, such changes were associated with suppressing brain antioxidant activity, inferred by lower DPPH radical scavenging activity, reduced total glutathione content, as well as the translocation and accumulation of NPs in the brain of the animals. In addition, we noted that the treatments induced DNA damage, evaluated via a single-cell gel electrophoresis assay (comet assay) applied to circulating erythrocytes of the animals. However, we did not observe a dose-response effect for all biomarkers evaluated and the estimated accumulation of PS NPs in the brain. The values of the integrated biomarker response index and the results of the principal component analysis (PCA) and the hierarchical clustering analysis confirmed the similarity between the responses of animals exposed to different doses of PS NPs. Therefore, our study sheds light on how PS NPs can impact mammals and reinforce the ecotoxicological risk associated with the dispersion of these pollutants in natural environments and their uptake by mammals. [Display omitted] • The toxicity of PS NPs is evaluated in male Swiss mice. • PS NPs induce anxiolytic-like behavior in mice after 20 days of exposure. • Mice exposed to PS NPs show impaired antipredatory response. • PS NPs induce a genotoxic effect. • Suppression of antioxidant activity is observed in mice exposed to PS NPs. [ABSTRACT FROM AUTHOR]

• MXene as an emerging 2D material for electrochemical sensor application. • Focus on the 2D MXene heterostructure for electrochemical sensing application. • MXene fabrication, properties and sensing performance. • Challenges of 2D MXene heterostructure in electrochemical sensor technologies. • Perspective for designing 2D MXene heterostructure sensors. The increasing environmental pollution and recurrent viral outbreaks have piqued researchers' interest in experimenting with new materials to improve electrochemical sensing properties and develop rapid, sensitive, low-cost, environmentally friendly, real-time detection devices that could generate data beneficial for health and environmental monitoring. Due to their wide range of applications, transition metal carbides and nitrides (MXene) have recently gained prominence in two-dimensional (2D) nanomaterials. MXene is a promising material for developing next-generation sensing applications due to its outstanding electronic and surface properties. Despite its numerous positive attributes, MXene exhibits a high proclivity for intersheet aggregation, lowering its electrochemical performance. To address this persistent issue, researchers attempted to integrate MXene with other 2D nanomaterials, nanoparticles, enzymes, or 3D materials, forming a composite with synergistic effects for enhancing sensing performance. Although plenty of literature is available in the sensor field, there is still a dearth of research on the two-dimensional MXene heterostructure, notably in electrochemical sensing applications. Thus, the main aim of this review is to elaborate on the 2D MXene heterostructure in the electrochemical sensing field. This review summarises different 2D MXene synthesis techniques, MXene characteristics, and sensing performance to provide a framework for developing high-performance sensors. [ABSTRACT FROM AUTHOR]

The use of solar energy is one of the most prominent strategies for addressing the present energy management challenges. Solar energy is used in numerous residential sectors through flat plate solar collectors. The thermal efficiency of flat plate solar collectors is improved when conventional heat transfer fluids are replaced with nanofluids because they offer superior thermo-physical properties to conventional heat transfer fluids. Concentrated chemicals are utilized in nanofluids' conventional synthesis techniques, which produce hazardous toxic bi-products. The present research investigates the effects of novel green covalently functionalized gallic acid-treated multiwall carbon nanotubes-water nanofluid on the performance of flat plate solar collectors. GAMWCNTs are highly stable in the base fluid, according to stability analysis techniques, including ultraviolet–visible spectroscopy and zeta potential. Experimental evaluation shows that the thermo-physical properties of nanofluid are better than those of base fluid deionized water. The energy, exergy and economic analysis are performed using 0.025%, 0.065% and 0.1% weight concentrations of GAMWCNT-water at varying mass flow rates 0.010, 0.0144, 0.0188 kg/s. The introduction of GAMWCNT nanofluid enhanced the thermal performance of flat plate solar collectors in terms of energy and exergy efficiency. There is an enhancement in efficiency with the rise in heat flux, mass flow rate and weight concentration, but a decline is seen as inlet temperature increases. As per experimental findings, the highest improvement in energy efficiency is 30.88% for a 0.1% weight concentration of GAMWCNT nanofluid at 0.0188 kg/s compared to the base fluid. The collector's exergy efficiency increases with the rise in weight concentration while it decreases with an increase in flow rate. The highest exergy efficiency is achieved at 0.1% GAMWCNT concentration and 0.010 kg/s mass flow rate. GAMWCNT nanofluids have higher values for friction factor compared to the base fluid. There is a small increment in relative pumping power with increasing weight concentration of nanofluid. Performance index values of more than 1 are achieved for all GAMWCNT concentrations. When the solar thermal collector is operated at 0.0188 kg/s and 0.1% weight concentration of GAMWCNT nanofluid, the highest size reduction, 27.59%, is achieved as compared to a flat plate solar collector with water as a heat transfer fluid. [ABSTRACT FROM AUTHOR]

Hydrothermal liquefaction (HTL) is a thermochemical depolymerization technology, also known as hydrous pyrolysis, that transforms wet biomass into biocrude and valuable chemicals at a moderate temperature (usually 200–400 °C) and high pressure (typically 10–25 MPa). In HTL, water acts as a key reactant in HTL activities. Several properties of water are substantially altered as the reaction state gets closer to the critical point of water, which can result in quick, uniform, and effective reactions. The current review covers the HTL of various feedstocks, especially lignocellulosic and high protein-containing feeds with their in-depth information of the chemical reaction mechanisms involved in the HTL. Further, this review gives insight and knowledge about the influencing factors such as biomass pretreatment, process mode, process conditions, etc., which could affect the efficiency of the hydrothermal process and biocrude productivity. In addition, the latest trends, and emerging challenges to HTL are discussed with suitable recommendations. [ABSTRACT FROM AUTHOR]

Selenium in wastewater is of particular concern due to its increasing concentration, high mobility in water, and toxicity to organisms; therefore, this study was carried out to determine the removal efficiency of selenium using iron and manganese-based bimetallic micro-composite adsorbents. The bimetallic micro-composite adsorbent was synthesized by using the chemical reduction method. Micro-particles were characterized by using energy-dispersive X-ray spectroscopy for elemental analysis after adsorption, which confirms the adsorption of selenium on the surface of the micro-composite adsorbent, scanning electron microscopy, which shows particles are circular in shape and irregular in size, Brunauer–Emmett–Teller which results from the total surface area of particles were 59.345m2/g, Zeta particle size, which results from average particles size were 39.8 nm. Then it was applied to remove selenium ions in an aqueous system. The data revealed that the optimum conditions for the highest removal (95.6%) of selenium were observed at pH 8.5, adsorbent dosage of 25 mg, and contact time of 60 min, respectively, with the initial concentration of 1 ppm. The Langmuir and Freundlich isotherm models match the experimental data very well. The results proved that bimetallic micro-composite could be used as an effective selenium adsorbent due to the high adsorption capacity and the short adsorption time needed to achieve equilibrium. Regarding the reusability of bimetallic absorbent, the adsorption and desorption percentages decreased from 50 to 45% and from 56 to 53%, respectively, from the 1st to the 3rd cycle. [ABSTRACT FROM AUTHOR]

A continuous mode fixed-bed up-flow column adsorption analysis was conducted utilizing Acacia nilotica sawdust activated carbon (ASAC) as an adsorbent for the adsorption treatment of toxic Indigo Carmine Dye (ICD). The effect on the adsorption characteristics of ASAC of the influent ICD concentration, flow rate, and column bed depth has been investigated. According to the column study, the highest efficiency of ICD removal was approximately 79.01% at a preliminary concentration of 100 mg/L with a flow rate of 250 mL/h at a bed depth of 30 cm and adsorption power of 24.67 mg/g. The experimental work confirmed the dependency of break-through curves on dye concentration and flow rate for a given bed depth. Kinetic models were implemented by Thomas, Yoon–Nelson, and Bed-depth-service-time analysis along with error analysis to interpret experimental data for bed depth of 15 cm and 30 cm, ICD concentration of 100 mg/L and 200 mg/L and flow rate of 250 mL/h, and 500 mL/h. The analysis predicted the breakthrough curves using a regression basin. It indicated that all three models were comparable for the entire break-through curve depiction. The characteristic parameters determined by process design and error analysis revealed that the Thomas model was better followed by the BDST and Yoon–Nelson models in relating the procedure of ICD adsorption onto ASAC. B-E-T surface area and B-E-T pore volume of ASAC were 737.76 m2/g and 0.2583 cm3/g, respectively. S-E-M and X-R-D analysis reveal the micro-porous and amorphous nature of ASAC. F-T-I-R spectroscope indicate distinctive functional assemblies like -OH group, C–H bond, C–C bond, C–OH, and C–O groups on ASAC. It could be computed that the ASAC can be used efficiently as an alternative option for industrial wastewater treatment [ABSTRACT FROM AUTHOR]