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Carbon paper is one of the most widely used gas diffusion layer substrate materials due to its stable performance, relatively low cost, and easy for subsequent processing. Water-soluble phenolic resin, which is more ecologically friendly than alcohol-soluble phenolic resin, was used to prepare carbon paper as the precursor of the carbon matrix. And the effect of different resin solution concentrations on the properties of carbon paper was explored. The results showed that the graphitization, electrical conductivity and mechanical properties of carbon paper increased with the increase of resin solution concentration. When the concentration of resin solution was 20 wt%, the performance of carbon paper was relatively optimal. The graphitization of the carbon paper reached 65.45%, the porosity reached 80.74%, the resistance value at 1 MPa pressure was only 7.61 mΩ cm2, the tensile strength was 1.57 MPa, and the elastic modulus was 1210.98 MPa. [ABSTRACT FROM AUTHOR]

To solve the durability problem caused by carbon corrosion in the porous carbon paper gas diffusion layer (GDL) of proton exchange membrane fuel cell (PEMFC), a Cr 7 C 3 ceramic coating on porous carbon paper by molten salt method was prepared. The obtained Cr 7 C 3 coating is dense and shows good adherent with the carbon paper. Based on the corrosion resistance testes, it is concluded that the Cr 7 C 3 coated carbon paper can keep high chemical stability in the long-time acid immersion accelerated corrosion tests and simulated cathodic proton exchange membrane fuel cells environment. The carbon paper with Cr 7 C 3 coating shows a small current density with a value of about 1.1 × 10−5 A cm−2 in the potentiostatic polarization test under 1 M H 2 SO 4 + 2 ppm HF at 70 °C and1.4 V SCE for 72 h. Meanwhile, the resistivity of carbon paper with Cr 7 C 3 coating prepared is 30% lower than that of pure carbon paper, and the conductivity is 1.5 times that of pure carbon paper. [ABSTRACT FROM AUTHOR]

Ni-doped WC/Mo 2 C composites for hydrogen evolution reaction (HER) were synthesized in situ grown on carbon fiber paper (CFP) by molten salt method in argon at 1000 °C for 6 h, named as Ni-xWC-y/2Mo 2 C@CFP. The effects of different W/Mo molar ratios (3:1, 2:1, 1:1, 1:2, 1:3) on the phase composition, microstructures, and HER performances were investigated. The results showed that the W/Mo molar ratio had a synergistic effect in HER of Ni-doped WC/Mo 2 C composites, and as W/Mo molar ratio at 1:1, the composite presented the best electrocatalytic activity. Meanwhile, its surface appeared to have a wrinkle-like structure, and the biphasic heterostructure emerged at the intersection of the dual-phase WC and Mo 2 C lattices. The introduction of a biphasic heterostructure could promote charge transfer and improve HER efficiency. Predictably, the electrocatalysts with the optimal W/Mo molar ratio 1:1 exhibited the best hydrogen evolution performance, needed only 43.7 mV overpotential to reach 10 mA cm−2 current density with a Tafel slope at 21.3 mV dec−1. In this work, the high-efficiency electrocatalysts of Ni-doped 1WC-1/2Mo 2 C@CFP have been prepared, which provides an insight into theoretical research of composite carbon-based electrocatalysts. [ABSTRACT FROM AUTHOR]

Aerogel composites reinforced by fibers have found extensive applications in the field of thermal insulation and energy conservation. However, the composites are hindered by their high infrared radiation transmittance and weak interface adhesion in practical applications. Herein, we designed and prepared a novel thin composite called 'fiber/whisker/aerogel paper' (SWAP) with a thickness of less than 1 mm. The SWAP integrated SiC nanowhiskers (SiC nw) as opacifiers and ultrafine SiO 2 fibers as reinforcement, fabricated through wet manufacturing and sol-gel process. The 'fiber/aerogel paper' (SAP) and SWAP exhibited low thermal conductivity at room temperature, measuring 0.025 W/(m·K) and 0.033 W/(m·K), respectively. Additionally, they exhibited low densities of 0.195 g/cm3 and 0.225 g/cm3, respectively. Notably, SWAP exhibited excellent high-temperature insulation performance, primarily due to its low infrared transmittance (50% at 3 μm). The incorporation of SiC nw and ultrafine SiO 2 fibers collectively enhanced the interfacial adhesion with the aerogel matrix even amidst rigorous testing (weight loss less than 3%). SWAP also demonstrated flexibility, high thermal stability, hydrophobicity, and flame resistance. Furthermore, a comprehensive investigation into the performance variations and influencing g factors of the material was conducted under different heat treatment conditions. This research provides guidance for the application of such materials under high temperatures. [ABSTRACT FROM AUTHOR]

The ZrO 2 fiber paper exhibits excellent thermal insulation properties, however, its limited mechanical strength and insufficient thermal stability hinder its widespread applications. The composite fiber papers, using mullite fibers possessing a high aspect ratio and exceptional thermal stability combined with ZrO 2 fibers, were fabricated via a vacuum-assisted filtration method. This method involved the successive stacking of composite fibers with alumina sol, using vacuum-induced directed water flow to create a layered structure reminiscent of nacre. The layered structure of the nacre, which demonstrates remarkable strength and hardness, has also served as a source of inspiration for the architectural design of the fiber paper. The tensile strength of pure ZrO 2 fiber paper was significantly enhanced by the addition of 7 wt% mullite fibers, resulting in a remarkable increase to 0.1805 kN/m. The paper exhibited exceptional resistance to bending, maintaining 96 % of its bending strength even after undergoing 100 cycles. The thermal shrinkage of the composite paper, containing 15 wt% mullite fibers, was reduced from 17.75 % observed in pure ZrO 2 fiber paper to a mere 1.32 % after undergoing heat treatment at a temperature of 1300 °C for 2 h. The composite paper, measuring 5 mm in thickness and consisting of 7 wt% compositions, displayed exceptional thermal insulation properties when exposed to a hot side temperature of 1370 °C. It effectively insulated temperatures up to approximately 1000 °C. [ABSTRACT FROM AUTHOR]

Rewritable paper is of great significance for environmental and sustainable development. Specially, the water rewritable paper based on hydrochromism has aroused extensive research interesting for being clean, convenient and compatible with the current ink jet printer. Nevertheless, previously reported water rewritable paper requires complex and time-consuming fabricating process. Here, we report a facile strategy to fabricate structural colored water rewritable paper simply via two step infiltration on commercially available paper. After infiltration of graphene laminates and SiO 2 colloidal spheres in sequence, the obtained paper is integrated with assembled graphene laminates (AGLs)/amorphous colloidal arrays (ACAs) hierarchical composite structure. Owing to the advantageous micro-topography, selective separation capacity and high visible light absorption property of the underlying AGLs, SiO 2 ACAs with vivid structure color can be realized. Moreover, the hydrochomism of the hierarchical composite structure is resulted from the synergistic contribution of the hydrophilic structural color and the visible light absorption property of AGLs. Our strategy is based on the environmental-friendly structural color and convenient to realized, which offers a promising alternative to rapidly fabricate colored water rewritable paper. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper describes the fabrication and characterization of porous SiC ceramics derived from highly-filled preceramic papers. The SiC ceramics were obtained by spark plasma sintering of stacked preceramic papers at temperatures of 2100 and 2200 °C under pressures of 5–60 MPa for 10 min. The microstructure and phase composition were analyzed by scanning electron microscopy and X-ray diffraction, respectively. Gas permeation tests were performed using hydrogen permeation cell at room temperature. It is revealed that the porosity of sintered SiC can be varied from 9 to 45 % depending on the sintering parameters. The shrinkage of the materials during spark plasma sintering occurs in four stages. The linear shrinkage value of the material increases from 7 to 47 % at 2100 °C and from 20 to 50 % for the samples sintered at 2100 and 2200 °C, respectively. Correlation dependencies between porosity and mechanical properties of the fabricated SiC were established. The obtained porous SiC ceramics exhibit high bending strength of 165 MPa and gas permeation flux of 78 molH 2 /m2/s at the porosity of 36 % that make it suitable for ceramic-based membranes. [ABSTRACT FROM AUTHOR]

This study presents a novel method for synthesizing hierarchical porous zinc oxide (ZnO) nanostructures by thermally decomposing green-synthesized hydrozincite. The hydrozincite was prepared at room temperature using zinc acetate dihydrate and calcium carbonate (CaCO 3) in cellulose printing papers as the precipitating agent. The resulting ZnO particles exhibit a distinctive flower-like morphology, consisting of porous nanosheets composed of interconnected nanoparticles. The average crystallite size of the hierarchically structured zinc oxide nanoparticles, as determined via X-ray diffraction Rietveld refinement method, was found to be 18.8 nm when calcined at 500 °C. However, with increasing calcination temperature to 600, 700, and 800 °C, the average crystallite size also increased to 24.3, 30.4, and 47.2 nm, respectively. The ZnO synthesized at temperatures of 500 °C, 600 °C, and 700 °C exhibits higher electrocatalytic activity toward the hydrogen evolution reaction (HER) compared to both the ZnO synthesized at 800 °C and commercial ZnO. This enhanced performance can be primarily attributed to the nanosized ZnO particles, which provide a substantial surface area, high accessibility of active sites, and fast charge transfer kinetics. In terms of photocatalytic activity, all the samples show HER improvement under the UV light irradiation, attributed to the generation of photoexcited charge carriers. The ZnO synthesized at 800 °C and the commercial ZnO exhibit greater enhancements in photocatalytic activity compared to the other samples. This implies that larger solid particles with fewer nanopores result in a greater exposed surface area for UV-light absorption. The hierarchically structured ZnO nanoparticles demonstrate promising electrocatalytic and photocatalytic activities, as well as stability, opening up potential applications in various fields, including energy conversion and environmental remediation. [ABSTRACT FROM AUTHOR]

Paper with simultaneous fire-resistance and hydrophobicity have greatly potential applications in the fields of packing, storage and delivering information, which attracts increasing attention recently. Different from the traditional cellulose-based paper which is extremely easily damaged by water and fire, a new type of highly flexible, fire-resistant and hydrophobic paper based on Si 3 N 4 nanowires and polydimethylsiloxane (PDMS) is reported. Specially, the Si 3 N 4 @PDMS core-shell nanowires with 3D interlocking structure are designed, in which the Si 3 N 4 nanowires act as the inorganic fire-resistant frameworks and the PDMS shell with low surface energy provides the hydrophobic surface. The Si 3 N 4 @PDMS core-shell nanowires are intertwined and interlaced to form a highly flexible Si 3 N 4 @PDMS paper. The tensile strength of Si 3 N 4 @PDMS paper is 6.19 MPa, indicating the good mechanical property. The obtained Si 3 N 4 @PDMS paper has the characteristics of writability, fire-resistance and hydrophobicity. The high thermal stability of Si 3 N 4 nanowires makes Si 3 N 4 @PDMS paper exhibit excellent fire resistance. No obvious change is observed for the commercial paper with Si 3 N 4 @PDMS paper as the fire-shielding layer after heating for 30 min. In addition, the contact angles of water droplets are all greater than 110° over the surfaces of Si 3 N 4 @PDMS paper after mechanical damages, chemical corrosions and thermal treatments. Si 3 N 4 @PDMS paper can be used in oil/water separation and oil collection. More importantly, Si 3 N 4 @PDMS paper can be used for writing without being damaged by fire or water. The present work may inspire the development and application of functional paper and is expected to become a breakthrough in the traditional paper industry. [ABSTRACT FROM AUTHOR]

The development of self-powered UV photodiode on green substrate is still a challenge. In this study, highly conductive Al doped ZnO (AZO) film was sputter-deposited on paper substrate at room temperature; subsequently, paper-based Schottky photodiodes were successfully fabricated by following Au-ZnO-Al and Au-ZnO-AZO-Al structure designs, respectively. These UV light-based devices operate successfully without external power. Au-ZnO-AZO-Al photodiode shows improved response and faster speed compared to Au-ZnO-Al photodiode. The one-dimensional Poisson simulation results demonstrate that the improvement is attributed to the strong electric field in the ZnO-AZO n-n+ high-low junction, thus, enhancing the collection rate and drifting speed of the photogenerated carriers. In addition, AZO can form favorable ohmic contact with the Al electrodes, further improving the device performance. The photo-response of the paper-based photodiode device shows high reproducibility and stability. Based on these outstanding results, we conclude that these paper-based electronic devices have great potential to replace conventional petroleum-based flexible electronic devices, thus, contributing to the green/sustainable development. [ABSTRACT FROM AUTHOR]

Carbon materials with layered structure and high conductivity are promising electrode candidates for dual-ion batteries (DIBs). However, the size mismatch of electrolyte ions and interlayer spacing of carbon materials limits the overall performance of DIBs. Thus, finding an effective strategy to adjust the interlayer spacing of carbon materials is of great importance. Here, we describe an efficient electrochemical strategy combining ion pre-intercalation and gas evolution reaction treatment to expand the interlayer spacing and modify graphene layers of carbon fiber papers. Furthermore, through the theoretical calculation we have demonstrated that the anion adsorption energy is reduced and kinetics is accelerated by the introduction of functional groups on the graphene layer. After the electrochemical modification, the discharge capacity of CFP increases more than 50%, the transfer resistance reduces even more than 40% and the capacity retains 94% after 1000 cycles in an ionic liquid electrolyte. These promising results demonstrate an effective and convenient method to solve the size mismatch issue, and therefore, arouse the potentials of carbon materials and other materials with layered structure for high performance DIBs. [ABSTRACT FROM AUTHOR]

Traditional slurry-based electrodes consist of heavy current collectors and electroactive materials with a low weight percentage, which inevitably increase the total weight and cost of lithium-ion batteries (LIBs). Consequently, the development of low-cost, lightweight, flexible and binder-free electrodes for LIBs is highly desirable but also greatly challenging. In this work, we report the synthesis of small ZnO nanoparticles uniformly embedded in N-doped carbon (NC) nanoplate arrays (NPAs) tightly grown on a N-doped carbon paper (NCP) substrate (ZnO/NC NPAs@NCP) through a facile metal-organic framework-engaged strategy. This electrode design not only avoids the utilisation of insulating polymer binders but also offers other advantages, including large electrode/electrolyte contact areas, abundant electroactive sites, good wettability of the electrolyte, fast electron/ion transport and efficient volume accommodation. Notably, the freestanding ZnO/NC NPAs@NCP electrode displays a high reversible capacity of 610 mA h g−1 (based on the mass of entire electrode) at a current density of 100 mA g−1 for 50 cycles and excellent long-term cycling stability (363 mA h g−1 at 500 mA g−1 for 200 cycles). Furthermore, a full cell employing ZnO/NC NPAs@NCP as the anode and commercial LiFePO 4 as the cathode is constructed, indicating the feasibility for practical application. Moreover, an analysis of the electrode kinetics confirms the favourable lithium-ion storage kinetics within the ZnO/NC NPAs@NCP electrode. The present work could provide a new approach to develop low-cost, lightweight and flexible electrodes for advanced energy storage. N-doped carbon nanoplate arrays (NPAs) embedded with small ZnO nanoparticles tightly grown on N-doped carbon paper (NCP) substrate is designed and exhibits excellent performance as a low-cost, lightweight, flexible and binder-free electrode for lithium-ion batteries. Image 1 [ABSTRACT FROM AUTHOR]

The commented paper claimed the preparation of a new compound, Bi 1/2 Li 1/2 Fe 1/2 W 1/2 O 3. By this commentary, we show that erroneous experimental evidence was provided for such claims. We demonstrate that the main phase in the commented paper is Bi 2 WO 6. [ABSTRACT FROM AUTHOR]

In this study, continuous carbon reinforced C f /(Ti 0.2 Zr 0.2 Hf 0.2 Nb 0.2 Ta 0.2)C–SiC high entropy ceramic matrix composites were additively manufactured through paper laminating (PL), direct slurry writing (DSW), and precursor infiltration and pyrolysis (PIP). (Ti 0.2 Zr 0.2 Hf 0.2 Nb 0.2 Ta 0.2)C high entropy ceramic (HEC) powders were synthesized by pressureless sintering and ball milling. A certain proportion of HEC powder, SiC powder, water, binder, and dispersant were mixed to prepare the HEC-SiC slurry. Meanwhile, BN coating was prepared on the 2D fiber cloth surface by the boric acid-urea method and then the cloth was cut into required shape. Additive manufacturing were conducted subsequently. Firstly, one piece of the as-treated carbon fiber cloth was auto-placed on the workbench by paper laminating (PL). Then, the HEC-SiC slurry was extruded onto the surface of the cloth by direct slurry writing (DSW). PL and DSW process were repeated, and a C f /HEC-SiC preform was obtained after 3 cycles. At last, the preform was densified by precursor infiltration and pyrolysis (PIP) and the final C f /HEC-SiC composite was prepared. The open porosity of the C f /HEC-SiC composites, with the HEC volume fractions of 15, 30 and 45%, were 7.7, 10.6, and 11.3%, respectively. And the density of the C f /HEC-SiC composites, with the HEC volume fractions of 15, 30 and 45%, were 2.9, 2.7 and 2.3 g/cm3, respectively. The mechanical properties of the C f /HEC-SiC composites increased firstly and then decreased with the HEC content increase, reaching the maximum value when the HEC volume fraction was 30%. The mechanical properties of the C f /HEC-SiC composites containing 45, 30 and 15% HEC were as follows: flexural strength (180.4 ± 14 MPa, 183.7 ± 4 MPa, and 173.9 ± 4 MPa), fracture toughness (11.9 ± 0.17 MPa m1/2, 14.6 ± 2.89 MPa m1/2, and 11.3 ± 1.88 MPa m1/2), and tensile strength (71.5 ± 4.9 MPa, 98.4 ± 12.2 MPa, and 73.4 ± 8.5 MPa). From this study, the additive manufacturing of continuous carbon fiber reinforced high entropy ceramic matrix composites was achieved, opening a new insight into the manufacturing of ceramic matrix composites. [ABSTRACT FROM AUTHOR]

Developing flexible gas sensors based on reduced graphene oxide (rGO) are highly promising for practical application, however, it is still challenging due to the sacrificed solution-processibility and mechanical properties after reduction. To address this issue, we here introduce solution-processed rGO and designed a flexible hydrogen (H 2) film sensor by coupling with Pd nanoclusters as the activators via direct colloids mixing and subsequent vacuum filtration. The rGO/Pd nanocluster film features with structural compactness, surface homogeneity, excellent mechanical flexibility, high-efficiency output, and simplification of compositing method. In addition, the film sensor exhibited high response value, fast behavior and stable sensing behavior towards high-concentration H 2 compared with bare rGO film owing to the significant activation role of Pd nanoclusters with ultrasmall sizes (average size: 3.3 nm). Conclusively, this work provides an ingenious and effective way for the design of rGO-based flexible sensor, and shows promise for efficient portable and cost-effective monitoring of environmentally H 2 gases leaks. [ABSTRACT FROM AUTHOR]

The cellulose derived carbon/graphene/ZnO aerogel composite was prepared as an electrode in order to investigate the electrochemical properties. Carbon aerogel was synthesized using paper as an available cellulose source, and the composite was obtained through a new and simple preparation method including the immersion of monolithic carbon aerogel in graphene oxide/Zn2+ suspension and subsequent chemical reduction and freeze drying. The morphology, functional groups and crystalline structure of the samples were studied with Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction Spectroscopy (XRD), respectively. Electrochemical performance of the prepared binder free electrodes was examined using Cyclic Voltammetry (CV), Galvanostatic Charge-Discharge (GCD) and Electrochemical Impedance Spectroscopy (EIS). The data revealed that flexible carbon/graphene/ZnO composite resulted in a low density (0.035 g cm−3) electrode with the capacitance of 900 mF cm−2 at a high current density of 10 mA cm−2, lower IR drop and high cyclic stability (capacitance retention of 96%) after 1000 cycles, at 10 mA cm−2. These features were due to the presence of 3D porous conductive network, highly reduced graphene oxide, and the formation of ZnO nanoparticles on graphene sheets. Moreover, polyaniline (PANI) was introduced to carbon/graphene/ZnO composite electrode using electro-oxidation method at different reaction time and aniline concentration in order to achieve remarkably improved capacitance of 2500 mF cm−2 (at 10 mA cm−2) and low charge transfer resistance. Also, after the supercapacitor device assembly, the capacitance was retained. Based on the results, the synthesized composite is a promising material for new generation of lightweight freestanding electrodes with the high electrochemical performance. [ABSTRACT FROM AUTHOR]

In an era of modern smart technology, flexible electrodes are of great interest for different energy conversion as well as energy storage applications like solar cells, all solid-state batteries, and supercapacitors. Flexible metal oxide-based paper electrodes are advantageous in comparison to conventional electrodes due to their economical synthesis, biocompatibility, and environment-friendly characteristics. However, the electrical conductivity of paper electrodes is limited because of the insulating nature of natural fibers employed as a binder for the flexible matrix of metal oxides. The current study is an attempt to tune the electrical properties of lignocelluloses (natural fibers) and titanium dioxide (TiO 2) based paper electrodes by facile electrodeposition technique. The crystalline parts (e.g., TiO 2 , Ag, and Au) of the prepared composite sheets were characterized by XRD analysis while the surface morphology was studied by SEM. FTIR was used to characterize the organic matter in LC fibers by identifying various molecular stretching and vibrational modes of C, H, and O-containing molecules. Electric permittivity was measured as a function of electric field frequency at room temperature which revealed the value of 23. 5 (at 1 kHz) for the sample LC/TiO 2 /Ag 9000s indicating the best charge storing capability of the sample. Impedance analysis was employed to identify various charge carrier mechanisms active in the sheets. It was found through impedance analysis that there is an active diffusion-controlled impedance mechanism of Au-coated samples causing an increased conductivity via the ionic diffusion. This diffusion-controlled conduction was modeled by the Warburg element. The enhanced conductivity due to ionic diffusion makes these samples more useful as electrodes. Cyclic voltammetry (CV) measurements of the electrodeposited samples established the increase in conductive properties and efficient kinetics of LC/TiO 2 paper sheets. The current study suggests that Ag and Au-coated paper electrodes can be potential candidates for energy conversion and storage applications. [ABSTRACT FROM AUTHOR]

In this work, a robust and flexible bilayered MXene/cellulose paper sheet with superhigh electrical conductivity was prepared via vacuum-assisted filtration and a subsequent hot-pressing process for electromagnetic interference (EMI) shielding applications. By tightly assembling few-layered MXene (f-Ti 3 C 2 T x) on the cellulose substrate via hydrogen bonds, an effective and interconnected conductive network was constructed in the paper sheet, resulting in a high electrical conductivity of 774.6–5935.4 S m−1 at various f-Ti 3 C 2 T x loadings. The highly conductive MXene layer can promptly reflect a great amount of incident EM waves, a process which preceded the transmission of EM waves in the cellulose matrix. Owing to the highly efficient reflection-dominated EMI shielding mechanism, the resultant bilayered MXene/cellulose paper sheets exhibit excellent EMI shielding effectiveness of 34.9–60.1 dB and specific EMI shielding efficiency of 290.6–600.7 dB mm−1. Moreover, the MXene/cellulose paper sheets demonstrated improved mechanical strength (up to 25.7 MPa) and flexibility due to the mechanical frame effect acted by the cellulose substrate. Consequently, the robust and flexible bilayered MXene/cellulose paper sheet is a promising candidate for application in next-generation electric devices. [ABSTRACT FROM AUTHOR]

The paper describes the structure and properties of preceramic paper-derived Ti 3 Al(Si)C 2 -based composites fabricated by spark plasma sintering. The effect of sintering temperature and pressure on microstructure and mechanical properties of the composites was studied. The microstructure and phase composition were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. It was found that at 1150 °C the sintering of materials with the MAX-phase content above 84 vol% leads to nearly dense composites. The partial decomposition of the Ti 3 Al(Si)C 2 phase becomes stronger with the temperature increase from 1150 to 1350 °C. In this case, composite materials with more than 20 vol% of TiC were obtained. The paper-derived Ti 3 Al(Si)C 2 -based composites with the flexural strength > 900 MPa and fracture toughness of >5 MPa m1/2 were sintered at 1150 °C. The high values of flexural strength were attributed to fine microstructure and strengthening effect by secondary TiC and Al 2 O 3 phases. The flexural strength and fracture toughness decrease with increase of the sintering temperature that is caused by phase composition and porosity of the composites. The hardness of composites increases from ~9.7 GPa (at 1150 °C) to ~11.2 GPa (at 1350 °C) due to higher content of TiC and Al 2 O 3 phases. [ABSTRACT FROM AUTHOR]

In this work, we demonstrated a novel and effective approach on the use of low-cost electrodes, an eco-friendly substrate and zinc oxide (ZnO) micro or nanorods (MRs or NRs, respectively) for building triboelectric devices (TENGs). The reported strategy focuses on using low-cost materials and fabrication processes. For the first time and without any pre-treatment, an aluminum recyclable paper from the milk carton (named ARP) was used as a substrate and TENG bottom electrode. A systematic study on the growing of ZnO structures on ARP by chemical bath deposition has been carried out. We found that the ZnO rods size, and resistivity of the TENG upper electrode considerably influence the power density of the device. Such sustainable, low-priced ZnO-based TENGs can produce up to 1.6μW/cm 2 output power density when operated at 50 Hz. The fabrication of an eco-friendly nanogenerator demonstrates the possibility of manufacturing low-cost, flexible, and large-area energy harvesting devices for future applications. [ABSTRACT FROM AUTHOR]

Abstract Al 2 O 3 /Cu-O composites were fabricated from the paper-derived alumina matrix infiltrated with a Cu-3.2 wt% O alloy. Paper-derived alumina preforms with an open porosity ranging from ∼ 14 to ∼ 25 vol% were prepared by sintering of alumina-loaded preceramic papers at 1600 °C for 4 h. Pressureless infiltration at 1320 °C for 4 h of the preforms with Cu–O alloy resulted in the nearly dense materials with good mechanical and electrical properties, e.g. fracture toughness up to 6 MPa m0.5, four-point-bending strength up to 342 MPa, Young's modulus up to 281 GPa and electrical conductivity up to 2 MS/m depending on the volume fraction of copper alloy in the composites. The technological capability of this approach was demonstrated using prototypes in various engineering fields fabricated by lamination, corrugating and Laminated Object Manufacturing (LOM) methods. [ABSTRACT FROM AUTHOR]

Abstract To meet the demand of modern flexible and disposable technology, directly collected lignocelluloses fibers and graphite composite are successfully fabricated with uniformly electrodeposited of thin layers of nickel, silver and nickel. These multilayers (Ni-Ag-Ni) were electrodeposited on lignocelluloses-graphite sheet by using three electrode setup at a constant reduction potential (−0.95 V) between the electrodes. Composition and nanostructures of these nanocomposites (LC-graphite-multilayers) were investigated by using energy dispersive x-ray spectrometry, field emission scanning electron microscopy, Raman spectroscopy, UV–VIS and impedance spectrometer. FE-SEM images revealed that Ni-Ag-Ni layers are uniformly integrated into LC-graphene matrix and EDX analysis confirmed the deposition of multilayers Ni and Ag. Dielectric analysis revealed the non-linear frequency dependent response of the multilayered deposited LC fibers based nanocomposite. Complex impedance spectroscopy analysis presented the multilayered deposited LC fibers based paper electrode for high-tech applications in optical and electronic devices. [ABSTRACT FROM AUTHOR]

Capillary infiltration and an in situ reaction between filter papers and zirconia powders were employed to synthesize laminated C/ZrC composite via vacuum impregnation and hot-pressing sintering at 1700 °C for 90 min under a pressure of 30 MPa. The microstructures and mechanical properties of the laminated C/ZrC composite were characterized via XRD, SEM, TEM analyses and the three-point bending test. The results indicated that the obtained composite exhibited a distinct laminar structure with alternating carbon and zirconium carbide layers. The composite had a bulk density of 1.89 g/m 3 , an open porosity of 21.6%, and a bending strength of 128 MPa. Typical non-brittle fracture behaviors are observed, and the composites show an elastic deformation at the beginning of the test, exhibiting a zigzagging rise until the maximum stress is reached. [ABSTRACT FROM AUTHOR]

Two-step growth of ZnO nanowires (NWs) on carbon fiber (CF) surface via hydrothermal synthesis was studied and their application in the preparation of paper-based friction materials by wet-forming process was also investigated. SEM and EDS results showed a dense and uniform ZnO NWs layer with vertical alignment was well established on surface of CFs. UV–vis spectra and XRD characterization further confirmed the formation of ZnO NWs on CFs surface. In comparison with control sample (paper-based friction material containing pristine CFs), the modified sample (paper-based friction material containing modified CFs) exhibited higher and more stable dynamic friction coefficient and greater wear resistance. It was concluded that the CFs@ZnO NWs had excellent tribological properties and was highly promising for wet paper-based friction material. [ABSTRACT FROM AUTHOR]

This paper describes the development and fabrication of pastes suitable for screen printing process using Ti 3 SiC 2 as the ceramic filler and ethyl cellulose as the binder. With the aim of obtaining high quality screen printed films, the influence of different amounts of Ti 3 SiC 2 filler (20–40 vol%) and binder (0–5 vol%) on the rheological properties of the pastes was investigated. Samples with higher viscosity, such as pastes containing 30 vol% and 40 vol% Ti 3 SiC 2 filler, regardless of the amount of ethyl cellulose, showed a higher printing quality compared to the samples with other compositions. The different paste compositions were screen printed onto paper-derived Al 2 O 3 substrates containing 28.6 ± 4.8% open porosity and sintered for 1 h under an argon atmosphere at 1600 °C. X-ray diffraction (XRD) measurements and scanning electron microscopy (SEM) analysis showed that the sintered films contained TiC as a primary phase and Ti 3 SiC 2 as a secondary phase. The partial decomposition of Ti 3 SiC 2 after sintering can be attributed to residual carbon from the organic additives, which decreases the thermal stability of this material. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this study was to increase the thermal resistance of a cellulose substrate, using films (a mixture of corundum-phase aluminum oxide, α-Al2O3, and a PVA solution). The corundum phase, which was chosen due to its high thermal resistance, was obtained using an adaptation of Pechini‘s polymeric precursor method. A polyvinyl alcohol (PVA) solution was used as a medium for mixing the oxide for subsequent deposition on a paper substrate. The materials were characterized by X-ray diffraction (XRD) and field emission gun scanning electron microscopy (FEG-SEM) coupled with energy dispersive X-ray spectrometry (EDS). The thermal behavior of the material was investigated by thermogravimetry (TG) and differential scanning calorimetry (DSC). The EDS results indicate that all the samples with deposited α-phase aluminum oxide contain the chemical elements (Al and O) originating from the α-phase, while the surface analysis indicated that the paper substrates were completely coated with the films. The TG and DSC analyses of the thermal resistance of the film-coated substrate indicate that it was impossible to increase the thermal resistance of the paper substrate because the events that occurred (decomposition of cellulose and pyrolysis of lignin, hemicellulose and PVA) took place in the same temperature range, as has been reported in the literature for samples of the paper substrate without deposited film. [Copyright &y& Elsevier]

Titania-based nanostructures and porous MnO 2 layer are deposited onto carbon fiber paper (CFP) conductive support using hydrothermal method. TiO 2 nanoparticles and leaf-like Na 2 Ti 3 O 7 nanosheets are synthesized through the hydrolysis of TiF 4 and post-treatment in NaOH aqueous solution. Electrochemical tests reveal that CFP@TiO 2 @MnO 2 has a better performance with areal specific capacitance of 744 mF cm −2 at 0.25 mA cm −2 , compared with that (600 mF cm −2 ) of CFP@Na 2 Ti 3 O 7 @MnO 2 . The possible mechanism is that TiO 2 has higher surface area and better electronic conductivity than those of Na 2 Ti 3 O 7 . However, the cycling performance of CFP@TiO 2 @MnO 2 is limited with capacitance retention of 17.7% after 1000 cycles while CFP@Na 2 Ti 3 O 7 @MnO 2 keeps this retention up to 59.9%. [ABSTRACT FROM AUTHOR]

Recently, microwave absorbing materials have been widely used with the development of electromagnetic wave technology such as 5G communication. It is urgent to develop low-cost electromagnetic wave absorbing materials to meet the increasing civil market demand. Herein, we report a novel and simple strategy to synthesize lightweight silicon carbide microwave absorber by calcining tissue and glass microspheres at high temperature. The results show that higher synthesis temperature can improve the crystallinity of SiC, generate more whiskers and reduce the impurity content. This in turn increases the dielectric loss of the material. The products synthesized at 1600 °C have excellent microwave absorption properties. At the thickness of 1.3 mm, it achieves a reflection loss of −32.5 dB and an effective absorption bandwidth of 4.1 GHz. This study broadens the way for the potential reuse of waste paper and glass, and provides a useful reference for the preparation of low-cost microwave absorbing materials. [ABSTRACT FROM AUTHOR]

Designing a high capacity and long cycle life MnO-based composite material for lithium ion batteries (LIBs) is still a great challenge because of the intrinsically low electrical conductivity and dramatic volume variations during lithiation/delithiation. In this paper, the MnO nanoparticles (MnO NPs) are recombined with multi-walled carbon nanotubes (MWCNTs) and reduced graphene oxide (r-GO) to rationally construct a novel MnO NPs@MWCNTs/r-GO multilayer sandwich structure via electrostatic interaction self-assembly and vacuum filtration processes. As a result, the MnO NPs are closely attracted in the conductive MWCNTs network, and the MWCNTs adsorbed on the surface of MnO NPs can be served as a soft and flexible carbon coating layer to self-adapt the huge volume expansion. For another, the r-GO between two MnO NPs@MWCNTs layers is the cause to form a free-standing paper, enhancing the transverse conductivity of the whole electrode simultaneously. These features will contribute to achieve excellent cycling stability and improved rate capability. [ABSTRACT FROM AUTHOR]

A flexible Bi 2 Se 3 /Graphene (BSG) composite paper has been prepared through a simple vacuum filtration method and a thermal reduction together. The BSG composite paper was directly used as anode electrode for lithium-ion batteries, without using any polymer binders or conduction additives. In contrast to the pure Bi 2 Se 3 , the BSG exhibits high reversible lithium ion storage capacities and superior cyclic capacity retention. It proposed that the superior lithium storage performances would be attributed to the special construction of the as-prepared BSG paper, in which the graphene can not only act as conductive network for electrodes, but also act as a frame to alleviate volume expansion or aggregation of Bi 2 Se 3 nanosheets during lithiation/delithiation. The as-prepared BSG paper shows a great potential as an anode materials for flexible Li-ion batteries. [ABSTRACT FROM AUTHOR]

Titanium dioxide is frequently used for the photocatalytic degradation of organic and inorganic pollutants present in the air, such as NOx. In this work, biomorphic anatase-based plates were manufactured using paper as an innovative template for fixation of TiO 2 . Ceramics with microstructure similar to paper were produced by infiltration of titanium isopropoxide (TTiP) and dopants, followed by hydrolysis in NH 4 OH, air drying, and calcination at temperatures up to 1000 °C. After heat treatment, the samples were characterized by XRD, TG/DTA, BET, EPR, and SEM. Anatase was obtained as the major phase at 800 °C and remained present up to 1000 °C. In tests of photocatalytic efficiency of produced plates for degradation of NO x gases, the best performance was obtained with a biomorphic anatase-based plate prepared using TTiP doped with 5% Zr 4+ , corresponding to 100% degradation of NO x in 35 min. [ABSTRACT FROM AUTHOR]

My comments concern the significant error in the crystallographic part of the commented papers. It was discovered that the studied nanocrystals are of sillenite type and the correct formula should be Bi 25 FeO 39 :Co,Ti and Bi 25 FeO 39 :Ni,Ti instead of BiFeO 3. Moreover, the type of unit cell is not correct. Due to the doping the new type of unit cell, previously unknown, was proposed for such crystals. It was found that the studied sample contains two slightly different phases of the sillenite type. The actual chemical composition of the studied crystals is not known. [ABSTRACT FROM AUTHOR]

Porous layers of paper-derived titanium silicon carbide (Ti 3 SiC 2 ), with a thickness ranging from 300 to 700 µm, were obtained by the heat treatment of preceramic papers containing Ti 3 SiC 2 as filler particles. The tearing strength of the preceramic papers was provided by cellulose fibers obtained from wood by the kraft pulping process, also described as pulp fibers, and ionic starches. Short pulp fibers with an average length of 657 µm were derived from short fibered hardwood (eucalyptus), while long pulp fibers with an average length of 1665 µm were derived from long fibered softwood (spruce, pine and larch). The fiber length of pulp fibers in the preceramic papers also influenced the microstructure and the properties of the paper-derived Ti 3 SiC 2 . Preceramic papers fabricated with short pulp fibers exclusively led to an average porosity of 18.6 vol% for the paper-derived Ti 3 SiC 2 , whereas the paper-derived Ti 3 SiC 2 had an average porosity of 45.3 vol% when preceramic papers with long pulp fibers only were used. The density of the paper-derived Ti 3 SiC 2 also affected the flexural strength, as could be shown by densifying preceramic papers using a calender. Thereby, the flexural strength of paper-derived Ti 3 SiC 2 could be increased by more than five times, from 13 MPa to 83 MPa. The purity of the paper-derived Ti 3 SiC 2 was found to be dependent on the purity of the raw materials and the process cycle, with TiC x and Al 2 O 3 impurities present in the ceramics. [ABSTRACT FROM AUTHOR]

Maghemite/silica composites were prepared by a facile and effective method. First a stable magnetic fluid (MF) was obtained by dispersing in toluene the maghemite nanoparticles, prepared by coprecipitation. Afterwards, maghemite nanoparticles were coated with silica by the hydrolysis and condensation of tetraethylorthosilicate. The structural, surface and magnetic characteristics of the composites were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) and vibrating sample magnetometer (VSM) measurements. Magnetic studies indicated the superparamagnetic behavior of the samples and the decrease of the saturation magnetization with the decrease of the magnetic fluid concentration. SEM images revealed the presence of agglomerated, spherical particles and TEM images showed both separated particles and multiple maghemite particles together, covered with silica layer. The close relationship between the concentration of maghemite nanoparticles and the color of composite materials was confirmed by diffuse reflectance spectroscopy. CIEL ⁎ a ⁎ b ⁎ analysis revealed the change of the composites׳ color from reddish-brown to light beige by decreasing the concentration of the maghemite nanoparticles. These results demonstrate that the maghemite/silica composites are suitable for the manufacture of magnetic paper with different degrees of whiteness that can be easily correlated with the concentration of the magnetic fluid used for their preparation. [ABSTRACT FROM AUTHOR]

My comments concern the errors in the crystallographic part of the commented paper. [ABSTRACT FROM AUTHOR]

Liquid-phase exfoliation of few-layer graphene in Coca-Cola ® was performed by a kitchen blender for rapid preparation of strain/light/humidity sensitive ink. The advantages of Coca-Cola as an exfoliating medium have been identified from the low structural defect (I D /I G = 0.39) and, moderate carbon to oxygen ratio (C/O = 2.6) obtained by the resulting graphene. It is discovered that a deposition of graphene on photo paper allowed a facile fabrication of smart paper that is able to detect minor strain (0 – 2.0%) with GF of 18.7. Meanwhile, the multi-responsiveness of ink towards light/humidity had been validated from the 10 s response time after the exposure to stimulants with the maximum resulting curvature degree of 16° and 14° under light and humidity changes, respectively. Finally, it is shown that our actuator is able to vertically lift a load (545 mg) from its initial flat position upon irradiation of light (200 mW/cm2). [Display omitted] [ABSTRACT FROM AUTHOR]

In this research, nanostructured green pigments of ZnO and Co (Co x Zn 1-x O) were synthesized using impregnated layer combustion synthesis under microwave radiation. Taguchi design of experiments was employed to systematically investigate the influence of variables including the type of fuel, cobalt percentage, fuel to oxidizer ratio and type of template (impregnated active layer) to minimize the average crystallite size of particles. Three different types of fuels such as xylitol, mannitol and sorbitol as well as three templates containing filter paper, cotton and sterile gauze were used for the first time for synthesizing Co x Zn 1-x O nanopigments. The optimum sample with the average crystallite size of 35 nm was synthesized in specific conditions including mannitol as a fuel, filter paper as a template, cobalt percentage of 7%, fuel to oxidizer ratio of 1.3× stoichiometry. XRD analysis demonstrated that whole samples have followed ZnO pattern representative pure phases in the final structure and well-doped Co2+. FESEM images revealed the homogeneity of the nanoparticles, with average particle size of 90 nm. As a result of colorimetric studies on the optimum sample a broad reflectance band nearby 520 nm demonstrates green region with L* = 58.19, a* = −13.65, C* = 14.35 and h° = 162.07. Results showed that the pigment calcination influences the reflectance intensity effectively (∼40%). Co percentage and template type are the most important factors affecting the final green product colorimetric properties. [Display omitted] [ABSTRACT FROM AUTHOR]

Although SiO 2 as an anode for lithium-ion batteries has an attractive high theoretical capacity (1965 mAh g−1), violent volume changes and poor electrical conductivity during alloying reaction limit its lithium storage performance. Here, we report a SNTs@NC composite anode loaded on flexible CNTs conducting paper (CP). The conductive network of CP promotes the rapid migration of Li ions and electrons, and the multi-dimensional skeleton formed by CNTs and SNTs@NC is conducive to the steady deposition of Li-ions. The excellent flexibility effectively defuses the impact of internal stress on the pole plate structure, showing a longer service life and better cycling stability compared with the traditional copper foil. The composite anode has the advantages of simple preparation, low cost and little environmental pollution, and as an innovative collector, CP effectively eliminates the influence of the volume effect of the anode on the electrochemical performance. This work may provide a novel way for the commercial development of SiO 2 anode or the preparation of flexible self-supporting electrode. [Display omitted] [ABSTRACT FROM AUTHOR]

The design and development of efficient nitride photocatalysts have attracted much attention. Herein, two-dimensional mesoporous Ta 3 N 5 is successfully synthesized through a simple sol-gel process with filter paper as a biological template and a combination of vacuum nitriding reactions. The prepared Ta 3 N 5 shows a wide light response range up to the near infrared (NIR) region due to the nitrogen vacancies generated from substitution of N3− for O2− ions during vacuum nitridation. Significantly, such a narrow bandgap (∼1.99 eV) still satisfies the redox potential of water splitting in thermodynamics. The experimental results show that the Ta 3 N 5 photocatalyst exhibits an enhanced hydrogen production rate of 34.6 μmol h−1 g−1, which is 3.9 and 2.1 times higher than that of Ta 2 O 5 and partial nitridation of Ta 2 O 5 (N–Ta 2 O 5), respectively. This enhanced photocatalytic performance could be attributed to the high specific surface area to provide reactive active sites, substitution of N3− for O2− ions to optimize the band structure, and special two-dimensional mesoporous structure to shorten the charge transfer distance. This work provides a new perspective for the preparation of two-dimensional nitride materials by a biological template method combining vacuum nitriding with enhanced photocatalytic performance. Two-dimensional mesoporous Ta 3 N 5 is synthesized by a simple sol-gel process with filter paper as a biological template and vacuum nitriding reaction, leading to an efficient photocatalytic performance. [Display omitted] • Two-dimensional mesoporous Ta 3 N 5 was prepared by a biological template. • The prepared Ta 3 N 5 shows a wide light response range up to the near infrared region. • The special two-dimensional structure shortens the charge transfer distance. • The Ta 3 N 5 photocatalyst shows a superior hydrogen production performance. [ABSTRACT FROM AUTHOR]

Single stabilizer-doped ZrO 2 has drawbacks such as inferior mechanical properties and thermal stability, making it difficult to obtain ZrO 2 ceramics with good density and high crystallinity. Thus, it is expected that ZrO 2 is doped and modified by two or more stabilizers. In this paper, the Sc 2 O 3 –Y 2 O 3 –ZrO 2 nanocomposite ceramic powders were prepared using ZrOCl 2 ⋅8H 2 O, ScCl 3 ⋅6H 2 O, and YCl 3 ⋅6H 2 O as raw materials and polyvinylpyrrolidone as dispersant. They calcined at diverse temperaturesby the pressureless sintering-assisted co-precipitation method after being pressed into disc shape. Sc 2 O 3 and Y 2 O 3 were added as ZrO 2 stabilizers to ameliorate the lack of insufficient mechanical properties and high-temperature stability of ZrO 2 ceramics caused by single doping. To study the stability of the phases at high temperatures, the specimens were characterized by TG-DTG, XRD, Raman, SEM, FT-IR, etc. The effects of different pH valuesand different calcination temperatures on the Sc 2 O 3 –Y 2 O 3 –ZrO 2 nanocomposite ceramics were investigated. It was demonstrated that ternary doping has very excellent phase stability. After calcination no monoclinic phase appeared, and the precursor samples were transformed from amorphous to a large amount of tetragonal phases and a few cubic phases. The samples at pH = 10 and calcination temperature of 1000 °C showed the best stabilization, the most uniform grain development, the best crystallinity, the most regular morphology, the highest tetragonal phase content of 89.2 %, the stabilization rate of 94.58 %, and the highest relative density of 98.75 %. The results show that this nanocrystalline powder can be used to prepare high-density nanoceramics. Furthermore, the activation energy for grain growth of Sc 2 O 3 –Y 2 O 3 –ZrO 2 nanocomposite ceramics was calculated as 13.87 kJ/mol. This paper provides a theoretical and experimental research basis for the controlled synthesis of Sc 2 O 3 –Y 2 O 3 –ZrO 2 nanocomposite ceramics using a pressureless sintering-assisted co-precipitation method. [ABSTRACT FROM AUTHOR]

This paper presents a complete analysis of the electrical and dielectric characteristics of N i C o 2 O 4 (NCO) bulk ceramic synthesized by the co-precipitation process as a future electronic device material. The structural analysis following the synthesis process revealed the formation of cubic-phase spinel NCO in the shape of nanospheres, with an approximate diameter of 25 nm. The present study aimed to examine the relationship between capacitance and conductance for the NCO under investigation, focusing on their frequency and temperature dependencies. The frequency range of interest ranged from 100 Hz to 1.5 MHz, while the temperature range considered was from 300 K to 450 K. The C/f plot has exhibited the phenomenon of negative capacitance, which may be attributed to the augmentation of polarization and the incorporation of additional minority carriers inside the structure. The dielectric parameters, such as permittivity, dielectric loss, alternating current conductance, and electrical modulus, were determined by capacitance and conductance measurements, taking into account their frequency and temperature reliance. All dielectric calculations were influenced by negative capacitance measurements. The negative capacitance feature of N i C o 2 O 4 is attributed to the ferroelectric properties of the Ni and Co elements in its composition. In conclusion, this paper has made a valuable contribution to the existing body of literature by enhancing our comprehension of the negative capacitance behavior and dielectric characteristics of the NCO. [Display omitted] [ABSTRACT FROM AUTHOR]

Silicon carbide fiber reinforced silicon carbide ceramic matrix composite (CMC SiC f /SiC) has the advantages of high temperature resistance, corrosion resistance, high strength, low density, and oxidation resistance. It is a high-performance advanced material in aerospace, energy and other fields. However, due to its high hardness, brittleness and anisotropy of fiber structure, the research on application-oriented high-quality processing technology has become a hot issue. In this paper, a new process of rotational thirteen-beam coupling nanosecond laser processing of CMC-SiC f /SiC was studied. The rotational thirteen-beam coupling ablation experiments were carried out on CMC-SiC f /SiC workpiece. A laser beam is divided into thirteen beams and rotated around the beam center by using a beam splitter element. The morphology, structure and composition of ablation holes at different speeds were observed and analyzed by laser confocal microscope, scanning electron microscope, and X-ray energy dispersive spectrometer. It is found that the characteristics of rotational beam coupling have a significant effect on the laser ablation morphologies. The results show that the ablation region of CMC-SiC f /SiC is elliptical due to the fast heat transfer of fibers. The energy density distribution of the waist section of the Gaussian like beam after beam coupling is similar to the "W" shape, and the central energy is lower than the surrounding energy, and the ablation holes also show a similar "W" shape. With the increase of rotational speed, the hole depth first decreased and then increased, the hole diameter and roundness first increased and then decreased, and the hole section was "W" shaped. The ablation area can be divided into five parts: the white granular SiO 2 solid coverage area, the recast layer, the lower recast layer, the molten layer, and the heat affected zone. The rotational characteristics will make the reaction intensity of the whole ablation area more uniform in the circumferential direction. The formation mechanism and element distribution of each part were explored. The research work in this paper will provide a new technical way for the high-performance application of CMC-SiC f /SiC. [ABSTRACT FROM AUTHOR]

Yttrium Iron Garnet (YIG) ferrites, characterized by their superior magnetic and dielectric attributes, are instrumental in advancing the development of microwave devices, particularly in enhancing high-frequency performance, integration, and miniaturization. This paper synthesizes YIG ferrite materials with the composition Bi 0.6 Y 1.4-x Ca 1+x Fe 4.5-x V 0.5 Ge x O 12 (x = 0.10 to 0.50, incrementing by 0.10) through the solid-state sintering method. It delves deeply into the mechanism by which Ca2+-Ge4+ ions substitution regulates the magnetic properties of BiV-YIG. The microstructural and magnetic properties of the samples were systematically tested and analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), vibrating sample magnetometry (VSM), and TE106 perturbation method. At a substitution content of x = 0.50, the substitution of Ge4+ ions for the Fe3+ ions at the d-site transforms the material from ferrimagnetic to paramagnetic, and the saturation magnetization of the sample drops to 132.74 G. By calculating the ferromagnetic resonance (FMR) linewidth using the law of approach to saturation, the study elucidates the negative impact of low saturation magnetization on FMR linewidth. The mechanisms proposed in this paper provide theoretical and experimental bases for reducing the FMR linewidth of high dielectric constant Bi-substituted YIG, paving the way for developing high-dielectric, low-loss YIG ferrite materials for microwave devices. [ABSTRACT FROM AUTHOR]

Ferroelectric photovoltaic (PV) materials have garnered considerable interest because of their distinctive switchable PV characteristics. Nevertheless, their ability to function within a wide range of ambient temperatures was previously constrained. This paper describes the construction of ferroelectric capacitors featuring an Au/PZT (Pb(Zr 0. 40 Ti 0.60)O 3)/FTO (SnO 2 :F) heterojunction through the utilization of the sol-gel technique. The performance analysis findings indicate that the PZT material, following optimization of annealing temperature, displayed strong ferroelectric properties and notable frequency-dependent dielectric behavior. An increase in temperature (25°C∼300°C) revealed that short-circuit current density J sc exhibited an upward → downward → upward trend and reached 399.6 μA/cm2 at 300°C. Energy band analysis showed the presence of spontaneous polarization and a large work function difference between the bottom electrode FTO and the top electrode Au (∼0.42 eV) created a strong built-in electric field in the PZT films, which was conducive to the photogenerated carriers' separation and greatly improved the PZT film ferroelectric PV. In this paper, transparent ferroelectric materials were demonstrated for the first time to exhibit a photoelectric responsivity of up to 1.77 mA/W at a temperature of 300°C, offering a practical strategy for the implementation of transparent ferroelectric photovoltaic devices in high-temperature environments, particularly those subjected to intense solar energy harvesting and conversion. [ABSTRACT FROM AUTHOR]

Declining the sintering temperature of enamel coatings is traditionally by reducing the content of network-forming agents (such as SiO 2) and increasing the content of flux (for example, alkali metal oxides), which will lower the density of the [- Si - O -] network structure, and adversely affect the corrosion resistance of enamel coatings. To ensure a low sintering temperature of enamel coatings as much as possible under a high SiO 2 content, it is essential to develop novel enamel coating formulas. However, abundant compositions of enamel coatings cause enormous verification workloads. To address this issue, this paper establishes a relational model of the compositions of enamel coatings and the sintering temperature using the back propagation (BP) neural network algorithm and proposes a formula that meets the requirement of lower the sintering temperature under a high SiO 2 content. When the SiO 2 content is 55 %, the sintering temperature can be diminished to around 400 °C. Furthermore, the influences of common enamel components on the sintering temperature are identified in this paper using the sensitivity algorithm. The obtained general law of formulas is that the total weight value of the formula at low sintering temperatures should be around −0.3. This paper can provide valuable theoretical guidance for subsequent research and expand the application range of enamel coatings. [ABSTRACT FROM AUTHOR]

In this paper, the nano silicon carbide with different sizes was prepared without hydrofluoric acid by using simple milling and related low temperature etching process in normal pressure. Also, it was the first time verified that 3-C dominated crystalline form of polycrystalline silicon carbide is etched, leaving the 6-H silicon carbide crystalline form by the Raman spectra and HAADF-STEM (high-angle-annular dark-field scanning transmission electron microscopy) imaging that. The application of the alkali etching technique could precise control the partial structural transformation of silicon carbide crystals to a certain extent, which further expands the traditional crystal structure transformation process. In addition, this paper demonstrates the silicon carbide composites in photocatalytic removal of various organic pollutants from aqueous solutions. In the photo degradation of MB (Methylene Blue), the removal rate of the modified silicon carbide shown ten times as much as the commercial silicon carbide. The 1-h degradation efficiency was significantly higher in the 50 μL H 2 O 2 system (100.0%, 86.8% and 89.9% removal of MB, Rhodamine B, Methyl Orange and Tetracycline hydrochloride, respectively). Furthermore, the unit spin concentrations of vacancy defects, superoxide radicals and hydroxyl radicals were quantitatively analyzed. The vacancy defects of the etched material were 1000 times higher than before, and the modified silicon carbide had higher transmittance to infrared and visible light. It strongly absorbs ultraviolet light. Conversely, the research on micron-sized silicon carbide loaded with Ag and Pt atoms found that it had a nitrogen fixation effect during the warming up process, in a nitrogen atmosphere. [ABSTRACT FROM AUTHOR]

To address the difficulties of continuous adjustment of visible transmittance of amorphous porous ceramics and their anti-fogging without treatment, this paper delicately combined "hydrochromism" and porous ceramics, and prepared water-induced SiO 2 transparent porous ceramics (TPCs) with high strength and adjustable transparency. The effects of adding solvents to the silica sol on their visible transmittance, integrity and porosity were studied, and their multifunctional applications were also investigated. Results showed that the addition of EG, ammonia and acetonitrile mainly affected the gel integrity, the porosity of amorphous TPCs, and their gelation time and light transmittance, respectively. The compressive strength, porosity, visible transmittance after drying and water absorption of the optimal TPCs prepared at 600 °C by adding the above three solvents were 23.95 MPa, 54.7 %, 43 % and 81 %, respectively. The transparency of TPCs could be adjusted from 3 % to 81 % by controlling their water content, and they had excellent thermal insulation and anti-fogging ability without any treatment, and the excellent anti-fogging performance is related to their hydrophilicity and uniform nanopore structures. Overall, this paper provides new strategies for lightweighting, anti-fogging, and continuous adjustment of visible transmittance of transparent ceramics, and the resulting lightweight TPC is an ideal candidate for applications in daylighting design, as well as thermal insulation and anti-fogging in high humidity environments. [Display omitted] • Water-induced highly transparent SiO 2 -based TPCs were prepared for the first time. • Controlling water content in TPCs has realized its continuous cycle from transparent to opaque. • TPCs possess the anti-fogging ability without any treatment. • TPC is an ideal candidate for applications in daylighting design, thermal insulation and anti-fogging. [ABSTRACT FROM AUTHOR]