Search Results (266)

By modulating the mass ratio of hydrothermal agents to cobalt/iron precursors, Co₃O₄ nanowires were successfully integrated into spinel-type Co/Fe@NF, forming a heterojunction anode for alkaline water electrolysis (AWE) hydrogen production. This Co₃O₄ nanowire-assembled CoFe₂O₄ nanosheet anode (Co/Fe(5:1)@NF) exhibits exceptional electrochemical oxygen evolution reaction (OER) performance, requiring only 221 mV overpotential to achieve 10 mA cm⁻². Sulfamethoxazole (SMX) was employed as a model pollutant to investigate the anode sacrificial material; it achieved approximately 95% SMX degradation efficiency, reducing the OER potential of 50 mV/10 mA cm⁻². SMX oxidation coupled with Co/Fe heterojunction structure partially substitutes the OER. Co/Fe heterojunction generates an internal magnetic field, which induces the formation of novel active species within the system. ·O₂⁻ is the newly formed active oxygen species, which enhanced the proportion of indirect SMX oxidation. Quantitative analysis reveals that superoxide radical-mediated indirect oxidation of SMX accounts for approximately 38.5%, Fe(VI) for 9.4%, other active species for 6.1%, and direct oxidation for 46.0%. The nanowire–nanosheet assembly stabilizes a high-spin configuration on the catalyst surface, redirecting oxygen intermediate pathways toward triplet oxygen (³O₂) generation. Subsequent electron transfer from nanowire tips facilitates rapid ³O₂ reduction, forming superoxide radicals (·O₂⁻). This study effectively driven by indirect oxidation, with cathodic hydrogen production, providing a novel strategy for utilizing renewable electricity and reducing OER while offering insights into the design of Co/Fe-based catalyst. Full article

Hierarchically porous polymers can unite macro-scale architected voids with micro-scale pores, enabling unique combinations of low density, high surface area, and controlled transport properties that are difficult to achieve with traditional methods. This review outlines the current advancements in creating such multiscale architectures using fused filament fabrication (FFF), the most widely used polymer additive manufacturing technique. Unlike earlier reviews that consider lattice architectures and foaming chemistries separately, this work integrates both within a single analysis. It begins with an overview of FFF fundamentals and how process parameters affect macropore formation. Design strategies for achieving macroporosity (≳100 µm) with a single thermoplastic are presented and categorized: 2D infill patterns, strut-based lattices, triply periodic minimal surfaces (TPMS), and Voronoi structures, along with functionally graded approaches. The discussion then shifts to functional filaments incorporating chemical or physical blowing agents, thermally expandable or hollow microspheres, and sacrificial porogens, which create microporosity (≲100 µm) either in situ or through post-processing. Each material approach is connected to case studies that demonstrate its application. A comparative analysis highlights the advantages of each method. Key challenges such as viscosity control, thermal gradient management, dimensional instability during foaming, environmental concerns, and the absence of standardized porosity measurement techniques are addressed. Finally, emerging solutions and future directions are explored. Overall, this review provides a comprehensive perspective on strategies that enhance FFF’s capability to fabricate hierarchically porous polymer structures. Full article

Transparent conductive electrodes (TCEs) are essential components in modern optoelectronic devices, including organic light-emitting diodes and solar cells, sensors, and flexible displays. Indium tin oxide has been the dominant material for TCEs due to its high transparency and conductivity. However, its brittleness, high cost, and increasingly limited availability pose significant challenges for electronics. Crack-template (CT)-assisted fabrication has emerged as a promising technique to develop metal mesh-based TCEs with superior mechanical flexibility, high conductivity, and excellent optical transmittance. This technique leverages the spontaneous formation of random and continuous microcrack networks in sacrificial templates, followed by metal deposition (e.g., Cu, Ag, Al, etc.), to produce highly conductive, scalable, and low-cost electrodes. Various crack formation strategies, including controlled drying of polymer suspensions, mechanical strain engineering, and thermal processing, have been explored to tailor electrode properties. Recent studies have demonstrated that crack-templated TCEs can achieve transmittance values exceeding 85% and sheet resistances below 10 Ω/sq, with mesh line widths as low as ~40 nm. Moreover, these electrodes exhibit enhanced stretchability and robustness under mechanical deformation, outperforming ITO in bend and fatigue tests. This review aims to explore recent advancements in CT engineering, highlighting key fabrication methods, performance metrics across different metals and substrates, and presenting examples of its applications in optoelectronic devices. Additionally, it will examine current challenges and future prospects for the widespread adoption of this emerging technology. Full article

Recently, a new class of materials with very high porosity and ultra-lightweight, namely, semiconductor aero-materials, has attracted the attention of many researchers. Semiconductor aero-materials, due to their special properties, can be used in the development of devices applied in biomedical, electronics, optoelectronic, energy conversion and storage, sensors, biosensors, catalysis, automotive, and aeronautic industries. Although aero-materials and aerogels are similar, different methods of obtaining them are used. Aerogels are synthesized from organic, inorganic, or hybrid precursors, the main characteristic being that they are gel-like solids with a high air content (99.9%) in the structure. Thus, three-dimensional (3D) interconnected porous network chains are formed, resulting in light solid-state structures with very high porosity due to the large number of air pores in the network. On the other hand, to obtain aero-materials with controlled properties such as morphology, shape, or the formation of 3D hollow structures, sacrificial templates are used. Thus, sacrificial structures (which can be easily removed) can be obtained depending on the morphology of the 3D structure to be obtained. Therefore, this review paper offers a comprehensive coverage of the synthesis methods of different types of semiconductor aero-materials that use ZnO tetrapod, ZnO(T), as a sacrificial template, related to the present and future perspectives. These ZnO(T) sacrificial substrates offer several advantages, including diverse synthesis processes and easy removal methods that occur simultaneously with the growth of the desired aero-materials. Full article

The “hand-waving sacrifice” is a large-scale sacrificial ceremony with more than 2000 years of history. It was passed down from ancient times by the Tujia ethnic group living in the Wuling Corridor of China, and it integrates religion, sacrifice, dance, drama, and other cultural forms. It primarily consists of two parts: ritual content (inviting gods, offering sacrifices to gods, dancing a hand-waving dance, etc.) and the architectural space that hosts the ritual (hand-waving hall), which together constitute Tujia’s most sacred ritual space and the most representative art and culture symbol. Nonetheless, in existing studies, the hand-waving sacrifice ritual, hand-waving hall architectural space, and hand-waving dance art are often separated as independent research objects, and little attention is paid to the coupling mechanism of the mutual construction of space and ritual in the process of historical development. Moreover, with the acceleration of modernization, the current survival context of the hand-waving sacrifice has undergone drastic changes. On the one hand, the intangible cultural heritage protection policy and the wave of tourism development have pushed it into the public eye and the cultural consumption system. On the other hand, the changes in the social structure of traditional villages have led to the dissolution of the sacredness of ritual space. Therefore, using the interaction of “space-ritual” as a prompt, this research first uses GIS technology to visualize the spatial geographical distribution characteristics and diachronic evolution process of hand-waving halls in six historical periods and then specifically analyzes the sacred construction of hand-waving hall architecture for the hand-waving sacrifice ritual space throughout history, as well as the changing mechanism of the continuous secularization of the hand-waving sacrifice space in contemporary society. Overall, this study reveals a unique path for non-literate ethnic groups to achieve the intergenerational transmission of cultural memory through the collusion of material symbols and physical art practices, as well as the possibility of embedding the hand-waving sacrifice ritual into contemporary spatial practice through symbolic translation and functional extension in the context of social function inheritance and variation. Finally, this study has specific inspirational and reference value for exploring how the traditional culture and art of ethnic minorities can maintain resilience against the tide of modernization. Full article

Inkjet printing has become a primary technique for manufacturing flexible and conformal electronics due to its digital control, design flexibility, and material compatibility. However, its direct deposition nature results in weak adhesion between metal films and substrates, as it mainly relies on van der Waals or capillary forces, which severely limits its broader application in these fields. To address this limitation, we proposed an additive–subtractive manufacturing method based on a water-soluble sacrificial layer. First, the sacrificial material is inkjet-printed onto the substrate. Then, ion sputtering is employed to bombard the surface with high-energy ions, enabling metal atoms to embed into the substrate and form a strongly adhered conductive layer. Finally, the substrate is immersed in water, dissolving the sacrificial layer and detaching the undesired metal, thereby achieving selective retention of the conductive pattern. Experimental results demonstrate that the optimized water-soluble material, with tailored viscosity and surface tension, enables a patterning resolution of ±10 μm. The adhesion strength of the sputtered metal layer is 5.2 times greater than that of inkjet-printed silver nanoparticles. This method was further applied to fabricate conductive patterns on a curved surface with a 91 mm radius confirming its feasibility and adaptability for complex 3D surfaces. Full article

As a core structure within the Qing Changling Mausoleum, a UNESCO World Cultural Heritage site, Long’en Hall preserves a relatively complete set of Qing dynasty imperial lacquered furniture. These furnishings provide critical physical evidence for studying Qing dynasty sacrificial rituals and the craftsmanship of court lacquerware. However, limited research has been conducted on the surface finishing techniques of such furnishings, posing challenges to their conservation and accurate restoration. This study focuses on representative furnishings from Long’en Hall—including an offering table, an incense pavilion, a throne, and a poke lamp—and employed a multi-method analytical approach comprising fluorescence microscopy (FM), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared (FTIR) spectroscopy. The analysis was conducted on the following two levels: the lacquer layer structure and material composition. The results show that the furnishings in the Long’en Hall adopt the typical structure of “lacquer ash layer–color lacquer layer”, and the color lacquer layer is composed of raw lacquer, tung oil, animal glue, and other natural organic ingredients as film-forming materials, supplemented with inorganic mineral pigments such as red lead (Pb₃O₄) and Au metal, which constitutes a stable organic–inorganic composite structure with the lacquer ash layer. The multi-analysis results show a good complementary and cross-corroboration relationship, providing the necessary technical support and a theoretical reference for Qing dynasty palace lacquer wood furniture as cultural relics worthy of scientific protection and imitation. Full article

In this study, a production method for ceramic shell macrocapsules and a high-temperature-resistant, polymer agent-based self-healing system was developed. Two types of macrocapsules were created by filling hollow ceramic capsules with high-temperature-resistant diallyl phthalate (DAP) resin, known for its thermal stability, and a peroxide-based curing agent. These capsules were incorporated into epoxy and DAP matrix materials to develop polymer composite materials with self-healing properties The macrocapsules were produced by coating polystyrene (PS) sacrificial foam beads with raw ceramic slurry, followed by sintering to convert the liquid phase into a solid ceramic shell. Moreover, FTIR, TGA/DTA, and DSC analyses were performed. According to the thermal analysis results, DAP resin can effectively function as a healing agent up to approximately 340 °C. In addition, quasi-static compression tests were applied to composite specimens. After the first cycle, up to 69% healing efficiency was obtained in the epoxy matrix composite and 63.5% in the DAP matrix composite. Upon reloading, the second-cycle performance measurements showed healing efficiencies of 56% for the DAP matrix composite and 58% for the epoxy matrix composite. Full article

The stabilization and upgrading of biomass and waste-derived pyrolysis oils requires development of reliable, active and low-cost upgrading catalysts. Basic natural materials can act as such catalysts and convert reactive oxygenates present in biomass pyrolysis oils. The conversion of furfural as a model compound has been conducted in an autoclave reactor at 200 °C to 300 °C using different calcium-based materials. CaCO₃, Ca(OH)₂, CaO, cement raw meal (CRM) and calcined cement raw meal (cCRM) were screened for their catalytic activity and characterized using X-ray powder diffraction (XRD) and X-ray fluorescence (XRF), nitrogen physisorption, carbon dioxide temperature programmed desorption (CO₂-TPD) and thermogravimetric analysis (TGA). CaCO₃ and CRM had low basicity and showed no catalytic activity at 200 to 300 °C. Notably, 90% conversion of furfural was achieved at 200 °C using Ca(OH)₂ with products being mostly furfural di- and trimers. For the basic CaO and cCRM, a temperature of 250 °C or above caused rapid polymerization of furfural. The proposed mechanism follows the Cannizzaro reaction of furfural, catalyzed by basic sites, polymerization of furfuryl alcohol, decarboxylation of furoic acid and decarbonylation of furfural, releasing CO, CO₂ and H₂O. Calcined cement raw meal showed the most promise for application as low-cost, sacrificial, basic catalyst. Full article

As Additive Manufacturing (AM) evolves from prototyping to full-scale production, improving geometric accuracy becomes increasingly critical, especially for applications requiring high dimensional fidelity. This study proposes a machine learning-based approach to enhance the geometric accuracy of 3D printed parts produced by Fused Filament Fabrication (FFF), a widely used material extrusion process in which thermoplastic filament is heated and deposited layer by layer to form a part. Our method relies on a Convolutional Neural Network (CNN) trained to predict a systematic deviation field based on 3D scan data of a sacrificial print. These scans are acquired using a structured light 3D scanner, which provides detailed surface information on geometric deviations that arise during the printing process. The predicted deviation field is then inverted and applied to the digital model to generate a compensated geometry, which, when printed, offsets the errors observed in the original part. Experimental validation using a complex reference geometry shows that the proposed compensation method achieves an 88.5% reduction in mean absolute geometric deviation compared to the uncompensated print. This significant improvement underscores the CNN’s ability to generalize across geometric features and capture systematic deformation patterns inherent to FFF. The results demonstrate the potential of combining 3D scanning and deep learning to enable adaptive, data-driven compensation strategies in AM. The method proposed in this paper contributes to reducing trial-and-error iterations, improving part quality, and facilitating the broader adoption of FFF for precision-demanding industrial applications. Full article

Research on hydrogen (H₂) production has been intensively investigated due to the critical need for transitioning from fossil fuels to cleaner energy sources. This study demonstrates a dual-purpose approach where water pollutant degradation and H₂ production occur simultaneously, eliminating the need for sacrificial materials and reducing costs. CuO-TiO₂ calcined xerogels were employed in solutions containing NaOH and acid black dye 1 (AB1). The CuO-TiO₂/AB1/NaOH system successfully degraded recalcitrant pollutants while producing H₂ under optimized conditions. H₂ evolution occurred at the photocatalyst holes due to AB1’s lower potential compared to water, while AB1 decomposition proceeded via O2^•− radical formation. X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) analyses showed sponge-like structures with 20 nm crystals. Polarization curves confirmed H₂ generation in the cathodic region. Bode diagrams of the CuO-TiO₂/AB1/NaOH system (0.3 M NaOH and 60 mg/L AB1) exhibited noble/passive behavior, consistent with the polarization curve data. Using 0.3–0.4 M NaOH and 60 mg/L AB1, 636–647 ppb H₂/g_catalyst was produced in 60 min, and only 0.07 mg/L AB1 was left as indicated by absorbance measurements at 618 nm. H₂ evolution decreased as dye degradation increased. The best system for dye degradation has a k constant of 0.066 min⁻¹ and R² of 0.99, contains 40 mg/L AB1, and runs at 40 °C, whereas the maximum dual performance required 0.5 M NaOH, yielding 5050 ppb H₂/g_catalyst. Full article

A new combined analysis of SEM-BSE and EDX images using Aphelion^TM software was proposed to describe the quantitative microstructure (quantity and neighborhood of sacrificial phases) of Al-Zn-Si-(Mg) coatings on steel. Three materials with different Al/Zn ratios and Mg content were analyzed. The quantitative microstructure allowed us to describe their corrosion behaviors in a chloride environment and understand their ranking for sacrificial protection of steel in accelerated corrosion tests. For the analyses, interdendritic Zn-rich or Mg-rich phases were expected to be more sacrificial to steel than Al-rich dendrites. Without Mg (AZ coating), Al-rich dendrites created a percolating network, but interdendritic phases did not, suggesting their sacrificial protection to steel to be very limited. Additionally, significant Zn gradients inside dendrites led to a premature coating consumption on the surface, creating new zones of naked steel. In the coatings with Mg (AZM), sacrificial interdendritic phases created a percolating network, which is expected to improve long-time sacrificial protection and contribute to a more uniform formation of Zn corrosion products. For Al content between 30 wt.% and 45 wt.%, a lowering of the Al/Zn ratio (L-AZM) increased the connectivity of the sacrificial interdendritic phases, which is expected to improve the long-term sacrificial effect. Accelerated corrosion tests of scratches in the steel coatings validated the hypotheses. Full article

The precise fabrication of semiconductor-based photonic crystals with tailored optical properties is critical for advancing photonic devices. GaP(111) is a material of particular interest due to its high refractive index, wide optical bandgap, and pronounced optical anisotropy, offering unique opportunities for photonic applications. Its near-lattice matching with silicon substrates further facilitates integration with existing silicon-based technologies. In this study, we present the growth of high-quality GaP(111) thin films using gas-source molecular-beam epitaxy (GSMBE), achieving atomically smooth terraces for the homo-epitaxy of GaP(111). We demonstrate the fabrication of photonic crystal cavities from GaP(111), employing AlGaP(111) as a sacrificial layer, and achieve a quality factor of 1200 for the cavity mode with resonance around 1500 nm. This work highlights the potential of GaP(111) for advanced photonic architectures, particularly in applications requiring strong light confinement and nonlinear optical processes, such as second-harmonic and sum-frequency generation. Full article

Flexible piezoresistive pressure sensors have great potential in wearable electronics due to their simple structure, low cost, and ease of fabrication. Porous polymer materials, with their highly deformable internal pores, effectively expand the sensing range. However, a single-sized pore structure struggles to achieve both high sensitivity and a broad sensing range simultaneously. In this study, a PDMS-based flexible pressure sensor with a bilayer porous structure (BLPS) was successfully fabricated using clamping compression and a sacrificial template method with spherical sucrose cores. The resulting sensor exhibits highly uniform pore sizes, thereby improving performance consistency. Furthermore, since different pore sizes and thicknesses correspond to varying Young’s moduli, this study achieves tunable sensitivity across a wide pressure range by adjusting the bilayer thickness ratio (maximum sensitivity of $0.063 {\mathrm{kPa}}^{-1}$ in the 0–23.6 kPa range, with a pressure response range of 0–654 kPa). The sensor also demonstrates a fast response time (128 ms) and excellent fatigue stability (>10,000 cycles). Additionally, this sensor holds great application potential for facial expression monitoring, joint motion detection, pressure distribution matrices, and Morse code communication. Full article

Epitaxial layers of water-soluble Sr₃Al₂O₆ were fabricated as sacrificial layers on SrTiO₃ (100) single-crystal substrates using the Pulsed Laser Deposition technique. This approach envisages the possibility of developing a new generation of micro-Solid Oxide Fuel Cells and micro-Solid Oxide Electrochemical Cells for portable energy conversion and storage devices. The sacrificial layer technique offers a pathway to engineering free-standing membranes of electrolytes, cathodes, and anodes with total thicknesses on the order of a few nanometers. Furthermore, the ability to etch the SAO sacrificial layer and transfer ultra-thin oxide films from single-crystal substrates to silicon-based circuits opens possibilities for creating a novel class of mixed electronic and ionic devices with unexplored potential. In this work, we report the growth mechanism and structural characterization of the SAO sacrificial layer. Epitaxial samarium-doped ceria films, grown on SrTiO3 substrates using Sr₃Al₂O₆ as a buffer layer, were successfully transferred onto silicon wafers. This demonstration highlights the potential of the sacrificial layer method for integrating high-quality oxide thin films into advanced device architectures, bridging the gap between oxide materials and silicon-based technologies. Full article