Preparation Of Materials Research Articles

Microstructure and property evolution of CuCr50 alloy prepared by aluminum thermal reduction-electromagnetic casting during hot forging process

To address the problems of low performance and density in CuCr50 alloys prepared by aluminum thermal reduction-electromagnetic casting, a synergistic process involving hot forging deformation to eliminate micropores in the alloy and heat treatment to modify the alloy was proposed. The effect of hot forging temperature on the microstructure evolution and performance strengthening of CuCr50 alloys during heat treatment was studied. The results show that the properties of CuCr50 alloys forged at different temperatures after heat treatment are better than those after direct heat treatment. After heat treatment, the conductivity of CuCr50 alloys forged at 800 °C reaches 22.41 MS/m, the density reaches 7.94 g/cm3, and the hardness reaches 112 HB, which are 73.59 %, 4.75 % and 37.59 % greater than those of the as-cast alloy, respectively. The microstructure analysis showed that the nano-Cr phase precipitated during the aging process of CuCr50 alloys after hot forging at 750 °C–850 °C had a semi-coherent relationship with the Cu matrix, which played a role in coherent strengthening. After hot forging at 900 °C, the precipitated Cr phase has an incoherent relationship with the Cu matrix, which played a role of dispersion strengthening. The performance test of 40.5 kV simulated vacuum interrupter shows that the breaking and chopping performance of the prepared CuCr50 contact material is obviously better than that of commercial products, which is expected to become a new process for the preparation of high performance CuCr contact materials.

Co-crosslinking and anchoring strategy: One-step preparation of N-doped porous carbon for supercapacitors and zinc ion hybrid capacitors

Porous carbon has been widely used in aqueous capacitors due to its wide source, high stability, and controllable preparation. However, the two-step preparation strategy of carbonization and activation with complex operation and serious energy consumption severely limits its further application. In this paper, resorcinol/urea-furfural resin was successfully prepared by using cleaner and greener furfural as raw material and co-crosslinking with resorcinol and urea under the action of catalyst. It is noteworthy that during the curing process, KOH is uniformly anchored inside the resin, so the system only needs one-step high-temperature pyrolysis to obtain a N-doped ant-nest-like three-dimensional interconnected porous carbon material. Consequently, the porous carbon exhibited an impressive specific capacitance of 283F g−1. The assembled symmetrical device shows a capacitance retention of 92 % after 50 000 cycles, showing excellent cycle stability. In addition, the assembled zinc ion hybrid capacitor exhibits a capacitance of 138 mAh g−1 and an energy density of 111 Wh kg−1. The one-step carbonization-doping-activation strategy of this bottom-up in-situ anchoring activator will provide further insights into the hierarchical pore structure design of porous carbon and facilitate the simple and efficient preparation of carbon materials.

Combining SiO2 NPs with biochar: a novel composite for enhanced cadmium removal from wastewater and alleviation of soil cadmium stress.

Cadmium (Cd) pollution in water and soil seriously threatens human health. Biochar and nanomaterials have high potential for solving the cadmium pollution problem due to their abundant pores and high specific surface area. Here, the preparation of the composite material SiO2NPs@BC (SBC) using SiO2 NPs (SN) and silkworm excrement biochar (BC) is described, along with its application in the remediation of cadmium-contaminated water and soil. Characterization experiments (SEM&EDS, BET, FTIR, XRD, and XPS) demonstrated that SiO2NPs@BC has a high specific surface area (46.5767m2/g), a well-developed pore structure (0.608375cm3/g), and abundant surface functional groups (Si-C, Si-O, Si-O-Si), providing active sites for the adsorption of Cd. Batch adsorption experiments in water showed that the adsorption capacity of SBC is higher than that of biochar (BC) and SN, with a maximum Langmuir adsorption capacity of 141.99mg/g. After five adsorption cycles, the removal rate of SBC was 73.04%, significantly higher than the 64.97% obtained for BC. The application of SBC not only improved the soil physicochemical properties by increasing the soil pH, the cation exchange capacity, and the soil organic matter content but also by reducing the amount of DTPA-Cd (24.6%) and the plant bioconcentration factor (28.28%) in the soil, converting Cd into more stable fractions (Red-Cd, Ox-Cd). Based on the results, SBC can effectively reduce Cd pollution.

Controlling the Relaxation Dynamics of Polymer Networks by Combining Associative and Dissociative Dynamic Covalent Bonds.

Dynamic polymer networks offer a promising solution to key challenges in polymers such as recyclability, processability, and damage repair. However, the trade-off between combining facile processability, fast self-healing, and high creep resistance remains a major obstacle to implementation. To overcome this, two very distinct dynamic covalent chemistries, Diels-Alder and transesterification, is combined in a single network. The resulting dual dynamic networks offer an unprecedented set of properties and control over the relaxation times. The system decouples the relaxation dynamics of the network from the spatial motifs, and the tuning of the ratio between chemistries enables to control of the relaxation dynamics over six orders of magnitude. Taking advantage of this control, the composition and rheological behavior is optimized to drastically improve the resolution for extrusion-based additive manufacturing of dynamic covalent networks. Additionally, two well-defined and separated stress relaxation peaks are observed at compositions close to 50% of each dynamic chemistry, accentuating the double character of the system's relaxation dynamics. This atypical situation, enables to preparation of self-healing materials with negligible creep, and with shape-memory properties solely leveraging the two distinct relaxation dynamics, instead of the glass transition temperature or the melting point.

Green Synthesis of Boric Acid Modified Bismuth Based Non-Toxic Perovskite Quantum Dots for Highly Sensitive Detection of Oxytetracycline.

In recent years, perovskite quantum dots (PQDs) have successfully attracted widespread attention due to their excellent optical properties. However, the instability and toxicity problems of perovskite quantum dots are the main obstacles limiting their applications. In this work, bismuth-based perovskite quantum dots were synthesized by a ligand-assisted reprecipitation method, based on which a novel boric acid-functionalized bismuth-based non-toxic perovskite quantum dots fluorescent sensor (Cs3Bi2Br9-APBA) that can be stabilized in the ethanol phase was prepared by a boron affinity technique. Based on the covalent binding interaction of Cs3Bi2Br9-APBA with oxytetracycline (OTC), a highly selective and sensitive method for the detection of OTC was developed, which effectively solved the problems of poor stability and toxicity in the application of perovskite quantum dots. Under the optimal conditions, the fluorescence intensity of the synthesized Cs3Bi2Br9-APBA was linear with the concentration range of 0.1 ∼ 18 µM OTC, and the detection limit could reach 0.0802 µM. The fluorescence detection mechanism was explored and analyzed by spectral overlap analysis, suppression efficiency study of observed and corrected fluorescence, and fluorescence lifetime decay curve fitting, the mechanism of OTC detection by Cs3Bi2Br9-APBA was identified as the inner filter effect (IFE). In addition, the sensor successfully realized the quantitative detection of trace OTC in the environment, and our study provides a new idea for the preparation of green perovskite materials with high stability and selectivity.

Eco-friendly, high-hydrophobic polybutylene succinate foam for oil-water separation

Polybutylene succinate (PBS) is an excellent biodegradable resin with good processability and toughness. The inherent hydrophobicity of this material makes it unique for the preparation of oil-water separation materials. In this paper, PBS foams with high hydrophobicity were prepared by the non-solvent induced phase separation (TINIPS) method using N, N-dimethylformamide (DMF) as a good solvent and anhydrous ethanol as a non-solvent. The effect of PBS concentration on the wettability and micro-morphology of this foam was experimentally investigated. The results showed that the foam had an optimal microporous structure with a water contact angle as high as 145° when the concentration of PBS was 30 %. It was further found that the saturated adsorption capacity of the foam was 5.55–12.39 times its mass and remained strong after 10 adsorption tests. Finally, the environmental adaptability of foams had been studied. The foams maintained their superhydrophobic and oil-absorbing properties in the presence of strong acids, strong bases, saturated sodium chloride solutions, and repeated abrasion. In addition, with the help of a pump-assisted adsorption device, oil-water mixtures can be separated continuously and quickly. This showed that the material had a broad application prospect in oil-water separation.

Two-step cathodic microwave electrodeposition for construction of Co9S3(OH)5@Ni(OH)2 hetero-structure as supercapacitor electrode materials

The preparation of two-phase electrode materials of Co9S8@Ni(OH)2 typically involves a laborious three-step process. In this study, a two-step cathode microwave electrochemical method was proposed for the fabrication of Co9S8@Ni(OH)2 electrode materials for supercapacitors, eliminating the need for precursor synthesis. This approach not only simplified the preparation process and saved time but also successfully produced a p-n heterostructure electrode material consisting of Co9S8@Ni(OH)2 phases, where the Co9S8 phase has a chemical formula of Co9S3(OH)5. This unique structure is capable of inducing an internal electrical field by facilitating the transfer of charge carriers from Co9S3(OH)5 to Ni(OH)2, thereby enhancing charge transfer kinetics. As a result, the electrode exhibited remarkable supercapacitive performance, achieving a high specific capacitance of 255.4 mAh g-1 (7.56 F cm-2) at 1 A g-1. Even at a 20-fold increase in charge/discharge current density, the specific capacitance remained high at 218.9 mAh g-1 (6.48 F cm-1), retaining 85.8 % of the initial capacity. Furthermore, the Co9S3(OH)6@Ni(OH)2 electrode materials demonstrated excellent durability, enduring 10000 cycles with a capacitance retention of 92.9 % of the initial value. An asymmetric supercapacitor constructed with Co9S3(OH)5@Ni(OH)2 as the anode and a commercial active carbon film as the cathode was able to power a red light diode continuously emitting light for up to 42 min.

Facile prepared high purity Cerium vanadate for simultaneous electrochemical detection of p-nitrophenol and 2,4,6-trichlorophenol

The incomplete inner subshell (i.e., 4f) makes rare-earth elements (REE) different from other elements in the periodic table. Incorporating an atomic number across the lanthanide group merely adds an extra electron to the inner 4f rather than the outer shell. To prove this, we tested Nd and Ce doped vanadates as facile and convenient way for simultaneous detection of para-nitrophenol and 2,4,6-trichlophenol via the electrochemical way over modified glassy carbon (GC) electrode (GC/CeVO4; NdVO4). For the materials preparation convenient single-step hydrothermal procedure was developed and resulting material (CeVO4) demonstrate high grade of crystallinity with average size through the crystalline plain (200) equal to 57.4 nm and absence of any additional phases. GC/CeVO4 electrode was applied for the pioneering study of simultaneous determination of p-nitrophenol (pNP) and 2,4,6-trichlorophenol (TCP) via the SWV method in Britton-Robinson buffer solution at pH5. The developed method of evaluation demonstrate the span of p-nitrophenol calibration graph in range from 0.2 μM to 100 μM with the detection limit 0.058 μM in the presence of 100 μM of 2,4,6-trichlorophenol. The TCP calibration graph comprise concentrations in range from 0.2 μM to 60 μM with the detection limit 0.111 μM in the presence of 100 μM of pNP. Simultaneous determination of pNP and TCP may be performed in range from 0.2 μM up to 60 μM with the limits of detection equal to 0.091 μM for pNP and 0.151 μM for TCP. GC/CeVO4 electrode demonstrate 9.2 % deviation of pNP signal and 11.3 % of TCP signal deviation within 8 cycles of measurement. Interference study was held with K+, Mg2+, Sr2+, ascorbic acid, citric acid, urea, phenol, resorcinol each taken in 10-fold excess, while the electrode demonstrated retention of signal level not less than 75 % of initial. Application of electrode to tap water investigation had shown the 15 % deviation of pNP signal while the TCP signal stays intact. The abovementioned makes GC/CeVO4 electrode promising for the evaluation of aromatics in wastewaters.

High-Active Surface of Centimeter-Scale β-In2S3 for Attomolar-Level Hg2+ Sensing.

Recognition layer materials play a crucial role in the functionality of chemical sensors. Although advancements in two-dimensional (2D) materials have promoted sensor development, the controlled fabrication of large-scale recognition layers with highly active sites remains crucial for enhancing sensor sensitivity, especially for trace detection applications. Herein, we propose a strategy for the controlled preparation of centimeter-scale non-layered ultrathin β-In2S3 materials with tailored high-active sites to design ultrasensitive Hg2+ sensors. Our results reveal that the highly active sites of non-layered β-In2S3 materials are pivotal for achieving superior sensing performance. Selective detection of Hg2+ at the 1 aM level is achieved via selective Hg-S bonding. Additionally, we evaluate that this sensor exhibits excellent performance in detecting Hg2+ in the tap water matrix. This work provides a proof-of-concept for utilizing non-layered 2D films in high-performance sensors and highlights their potential for diverse analyte sensing applications.

Ammonia controlled synthesis of NiO nanosheet arrays for high-performance electrochromic-supercapacitors

To optimize the synthesis process and improve the electrochromic and energy storage performance of NiO, in this paper, an ammonia hydrothermal method is used to prepare NiO nanosheet array electrodes with dual-functions of electrochromic and energy storage. When the concentration of ammonia reaches pH = 11.5, the prepared electrode exhibits optimal optical modulation capability (79.2 % at 620 nm). Additionally, this electrode also provides a large area specific capacitance (69.5 mF/cm² at 0.2 mA/cm²), good rate capability (maintaining 46.7 mF/cm² at 1.0 mA/cm²), and excellent capacitive stability (retaining 96 % of the initial capacitance after 5000 cycles). These excellent performances are mainly attributed to the hierarchical assembled nanosheets structure, which has a large active surface area and short ion transport paths. Furthermore, the uniform and interlinked self-assembled structure, as well as the preset seed layer significantly enhance the film's structural stability and the adhesion to the substrate. Notably, we also construct electrochromic-supercapacitors (ECSCs). During the charging process, two series-connected ECSCs turn dark brown and light up an LED lamp, while during the discharging process, the ECSCs gradually becomes colorless, and the LED lamp goes out. This study provides directions for the preparation of novel dual-functional visual energy storage materials and boosts the development of dual-functional electrochromic-energy storage devices.

Characterisation Analysis of Sulphur and Phosphorous Doped and Co-doped Graphitic Carbon Nitride (g-C3N4) Materials

Graphitic carbon nitride (g-C3N4) is tailored with doping of different non-metals (Sulphur and Phosphorus). For synthesis through thermal condensation method, the mixtures of urea and dopant with diverse concentrations have been added for preparation of materials. The basic effect of doping and its concentration on the structural morphology and absorption spectra of the samples is investigated in detail. Pure g-C3N4 suffers from high recombination rate of photogenerated electron-hole pairs resulting in low photocatalytic activity. Different techniques like X-ray diffraction (XRD), Scanning electron microscopy (SEM), Fourier transforms infrared (FTIR) spectroscopy, and Photoluminescence spectroscopy (PL) have been used for the characterization. X-ray diffraction studies confirm the formation of the g-C3N4 structure and SEM images reveal crumpled sheets and irregular plate like shapes of the doped graphitic nitride samples. FTIR analysis identify the presence of surface amino (N-H) and water (O-H) groups, cyano terminal group (C≡N), (C≡C), C–N) and (C=N) bonds and breathing mode of the tri-s-triazine units in the samples. PL spectra shows that the sulphur and phosphorus co-doped PSGCN (8 wt.%) sample is better for photocatalytic activity.

A novel application of waste poplar sawdust biochar: preparation of a shape-stable composite phase-change material with excellent thermal energy-storage performance

ABSTRACT The practical application of phase-change materials (PCMs) is limited due to leakage and low thermal conductivity. In this study, waste poplar sawdust (PW) and its derived biochar (PWC) were used as encapsulation materials, with stearic acid (SA) as the phase-change material, to successfully prepare composite phase-change materials with no leakage and high thermal conductivity. The microstructure and pore structure of PW and PWC were studied through SEM and nitrogen adsorption–desorption curves. The analysis results of FTIR, XRD and TGA indicated SA/PW and SA/PWC had excellent chemical compatibility and thermal stability. Excitingly, compared to SA/PW, SA/PWC exhibited higher latent heat and thermal conductivity. DSC results showed that the phase-change latent heat of SA/PWC can reach 100 J/g, which was 21% higher than that of SA/PW and the thermal conductivity increased by 87% times compared to SA/PW . In addition, SA/PW and SA/PWC still exhibited good thermal energy storage capacity after 200 thermal cycles. This research not only effectively resolved the leakage and low thermal conductivity challenges associated with PCMs but also introduced a novel utilization strategy for waste poplar sawdust, thereby significantly expanding its application potential.

DNA-Based Complexes and Composites: A Review of Fabrication Methods, Properties, and Applications.

Deoxyribonucleic acid (DNA), a macromolecule that stores genetic information in organisms, has recently been gradually developed into a building block for new materials due to its stable chemical structure and excellent biocompatibility. The efficient preparation and functional integration of various molecular complexes and composite materials based on nucleic acid skeletons have been successfully achieved. These versatile materials possess excellent physical and chemical properties inherent to certain inorganic or organic molecules but are endowed with specific physiological functions by nucleic acids, demonstrating unique advantages and potential applications in materials science, nanotechnology, and biomedical engineering in recent years. However, issues such as the production cost, biological stability, and potential immunogenicity of DNA have presented some unprecedented challenges to the application of these materials in the field. This review summarizes the cutting-edge manufacturing techniques and unique properties of DNA-based complexes and composites and discusses the trends, challenges, and opportunities for the future development of nucleic acid-based materials.

Peningkatan teknologi bagi agroindustri pliek-u sebagai upaya pelestarian kearifan lokal di Aceh [Technology improvement on pliek-u agroindustry as an effort to maintain a local wisdom in Aceh

Pliek-u is a specialty food product in Aceh with local wisdom values that should be preserved. The Program of Community Service Based Product (PKMBP) aimed to improve the pliek-u agro-industry by adapting simple processing technologies so that it could lighten work, produce quality products, and attract the interest of the younger generation as pliek-u entrepreneurs in future. The method applied consist of surveys, preparation of tools and materials, assembly of a solar tunnel dryer type Hohenheim Aceh and a hydraulic press, training and dissemination of technology through field schools, and evaluation of the program with pre-tests and post-tests. Data analysis was carried out using the Wilcoxon rank test with alpha of 5%. The results of the program were the construction of 1 unit of Hohenheim Aceh tunnel dryer, 1 unit of hydraulic press, and the implementation of training and dissemination activities which have been published in the form of videos on YouTube media and press releases through online media. The results of the Wilcoxon rank test also showed that of the 13 participants whose data were valid, 100% of participants received positive rankings and the pre-test scores were significantly different from the post-test scores. Thus, it can be concluded that the program carried out has contributed to increasing the knowledge, expertise capacity, and interest of participants in pliek-u processing technologies since the profile of conventional agroindustry can be transformed to be better agroindustry by the use of solar tunnel dryer type Hohenheim Aceh and hydraulic press. In addition, the use of technologies will ensure the halal requirement of pliek-u.

Preparation and Characterization of Urea-Modified Lignin-Derived Porous Carbon Materials and their CO<sub>2</sub> Adsorption Properties

Present study, activated carbon was precarbonised and chemically activated to prepare activated charcoal from different lignins , and their adsorption properties had been investigated. The influences of carbon source selection with urea modification on the CO2 adsorption performance of the materials were investigated. The selectivity, warmth of adsorption and cyclic steadiness of the materials had been in addition tested. The urea-modified porous carbon materials were prepared using dealkylated lignin (LCC), calcium lignosulfonate (CLS) and sodium lignosulfonate (SLS) as carbon precursors, KOH as activator and urea as nitrogen dopant. The CO2 adsorption values of the LCC-0.5N samples had been 5.52 mmol/g and 3.90 mmol/g at 1 bar, 273 K and 298 K, respectively, and were obtained in 10 successive adsorption-desorption cycles. The CO2 adsorption ability remained stable and greater than 110 mg/g after 10 consecutive adsorption-desorption cycles.

Sulfur-containing cellulose esters for selectively anchoring gold for water catalytic decontamination

The facile preparation of sustainable sulfur-containing polymer functional materials has been obtained great attention due to their chemical reactivity and metal complexing ability. In this study, taking the solution properties advantages of the newly developed cellulose solvent system of DBU/DMSO/CO2, thiol and disulfide bond functionalized cellulose ester (TDSCE) was facilely prepared via in-situ tandem transesterification and oxidation reaction by using methyl 3-mercaptopropionate, without adding any external catalyst. The synthetic protocol was featured by that the DBU not only acted as reagent for the dissolution of cellulose, but also catalysts for the transesterification of cellulose with methyl 3-mercaptopropionate to yield cellulose 3-mercaptopropionate (Cell-MP) with maximum degrees of substitution (DS) of 0.77, and an oxidant for the partial oxidation of Cell-MP to produce a cellulose methyl 3,3′-disulfanediyldipropionate (Cell-MDSP) with maximum DS of 0.36 mixed ester, respectively. With successful introduction of thiol and disulfide bond into the cellulose backbone, the TDSCEs indicated desirable selective absorption of Au3+ from mimic heavy mental ions waste water due to the sulfur-Au chemistry with maximal adsorption capacity for Au3+ of 415.2 mg/g. The subsequent reduction of Au3+ into gold nanoparticles (Au NPs) fabricated a robust TDSCE-2@Au NPs composite catalyst with high catalytic activity for the hydrogenation treatment of water pollutes, such as 4-nitrophenol (4-NP)and azo dyes.

Integrated manufacturing of powder metallurgy preparation-thixoforming for Al0.8Co0.5Cr1.5CuFeNi HEA: Excellent formability and enhancement by in-situ generated Al2O3 in liquid phase

Thixoforming displays wild application prospects in manufacturing Cu containing high entropy alloy (HEA) product. In current work, we proposed a novel manufacturing strategy on powder metallurgy preparation-thixoforming for Cu containing HEAs, integrating material preparation, shaping and strengthening objectives. During thixoforming, oxide in-situ generation in liquid phase was utilized to reinforce soft phase, achieving the strengthening of component. Based on this strategy, manufacturing of disc-shaped component for a model Al0.8Co0.5Cr1.5CuFeNi HEA was studied. Compared to 1175 °C thixoforming, room-temperature strength experiences a breakthrough increase at 1200 °C and 1225 °C, accompanied by an increase in yield strength of 323.8 MPa and 314.8 MPa, an increase in ultimate strength of 374.2 MPa and 470.0 MPa, meanwhile, fracture strain improves, which is caused by a considerable amount of in-suit generated Al2O3. Homogeneous and almost defect free microstructure obtained under higher temperature conditions ensures uniformity of mechanical properties for the whole component. As thixoforming temperature increases, preferred orientation of grain fiber shape becomes random, plastic deformation of solid grain (PDS) turns to flow of liquid incorporating solid particles (FLS), sliding between solid particles (SS) during material flow filling, which effectively reduces material damage risk caused by strain localization. In-situ generated Al2O3 in liquid phase helps to hinder crack propagation and blunt crack tip in Cu rich soft phase. Al2O3 only strengthens soft phase, relieving mismatch of strength-plasticity properties between soft and hard phase, accordingly, failure of soft phase is delayed and simultaneous improvement of strength and plasticity is achieved.

Theoretical and Empirical Justifications for The Development of the Questionnaire “Subjective Evaluation of Lukism in Humor”

Introduction. The paper deals with the problem of lookism (discrimination based on appearance) on the example of evaluating humorous posts and memes, which in various social situations can act as triggers of lookism. In order to diagnose sensitivity to Lukism in jokes, we attempted to prepare a basic description of the future structure of the methodology by testing a number of statements obtained by other authors in relation to different types of jokes. The novelty of the study lies in the description of the stages of preparation of the stimulus material, which allows us to study the peculiarities of perception of humor that ridicules the features of appearance and sensitivity to such jokes depending on the respondent’s experience (as a victim or a witness). Objective. To test a number of assumptions that are essential for the development of a questionnaire to examine the subjective evaluation of Lukism in humor. Materials and Methods. The study was conducted in five stages, a total of 410 participants (54 men, 356 women), aged 19 to 46 years, each stage included consideration of different components of perception and evaluation of humor in terms of the perception of it as offensive/containing lukism. Results. At each stage the peculiarities of perception of humorous posts that are distributed in social networks were revealed. It was revealed that the way of design (textual, textual-visual, as well as peculiarities of using different visual components), as well as the personal experience of respondents who faced situations of Lukism and self-assessment of respondents’ appearance influence the perception of a joke as containing or not containing Lukism, as well as the prediction of its assessment by other people as “offensive”. Discussion. Considering memes as complex, multilevel texts of identity, we see in them a significant potential for studying social norms, stereotypes and attitudes about appearance and sensitivity to the assessment of it as “non-standard” and a target for jokes. At the empirical level, we have identified a number of requirements for the selection of jokes to be included in the questionnaire: uniformity of design, use of “swear words”, visual content (images of “realistic people”), etc. An approximate structure of the future questionnaire is also presented.

Improved Electromagnetic Interference Shielding Efficiency of PVDF/rGO/AgNW Composites via Low-Pressure Compression Molding and AgNW-Backfilling Strategy.

Silver nanowires (AgNWs) have excellent electrical conductivity and nano-sized effects and have been widely used as a high-performance electromagnetic shielding material. However, silver nanowires have poor mechanical properties and are prone to fracture during the preparation of composite materials. In this study, PVDF/rGO/AgNW composites with a segregated structure were prepared using low-pressure compression molding and the AgNW-backfilling process. The low-pressure compression of the composite significantly improves its electromagnetic shielding performance because the low-pressure process can maintain the AgNWs' integrity. The backfilled AgNWs played a vital role in increasing the path of electromagnetic wave propagation and the absorption of electromagnetic waves. The backfilled amount of AgNWs was only 1 wt%, which increased the composite material's conductivity by one order of magnitude. The total electromagnetic interference shielding (SET) of the composite materials increased by 23.3% from 24.88 dB to 30.67 dB. The absorption contribution (SEA/SET) increased from 84.2% to 92.8%, significantly improving the electromagnetic interference shielding and the absorption contribution of the AgNWs in the composites. This was attributed to the backfilling of the porous structure by the AgNWs, which promoted multiple reflections and enhanced the absorption contribution.

Bioderived carbon aerogels loaded with g-C3N4 and their high Efficacy removing volatile organic compounds (VOCs)

Indoor air pollution, predominantly caused by volatile organic compounds (VOCs), poses significant health hazards when concentrations surpass critical thresholds. Using waste corn straw as carbon source and urea as nitrogen source, straw derived carbon aerogel (CAGH) loaded with g-C3N4H2O-N2-450–3 h was successfully prepared by hydrothermal and water-assisted calcination. Following water-assisted regulation, g-C3N4H2O-N2-450–3 h on CAGH exhibited a mixed structure comprising honeycomb and two-dimensional filaments, while the growth of g-C3N4H2O-N2-450–3 h was uniformly distributed on carbon aerogel in a line-surface combination fashion. This innovative binding method not only enhanced the loading capacity of g-C3N4 and the mechanical elasticity of aerogel, but also exposed a large number of adsorption sites, resulting in a significant increase in its adsorption capacity for VOCs, exceeding that of commercial activated carbon (AC). In comparison to pure g-C3N4, CAGH exhibited an expanded photo-response range. Under the exposure of visible light, CAGH proved highly effective in eliminating 73.87 % of toluene. In addition, it has demonstrated efficient removal of formaldehyde and acetone VOCs with good cyclic stability. Therefore, this work aims to reduce the emission of pollutants at source and provide an effective and economical strategy for the preparation of clean building materials from renewable materials, with potential applications in the environmental field.