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Paraffin wax (PW) has significant potential for spacecraft thermal management, but low thermal conductivity and leakage issues make it no longer sufficient for the requirements of evolving spacecraft thermal control systems. Although free-state expanded graphite (EG) as a thermal conductivity enhancer can ameliorate the above problems, it remains challenging to achieve higher thermal conductivity (K) (>8 W/(m·K)) at filler contents below 10 wt.% and to mitigate the leakage problem. Two preparations of thermally conductive shape-stabilized PW/EG composites, using the pressure-induced method and prefabricated skeleton method, were designed in this paper. The expanded graphite formed a nanoscale porous structure by different methods, which enhanced the capillary action between the graphite flake layers, improved the adsorption and encapsulation of EG, and alleviated the leakage problem. The thermal conductivity and the latent heat of the phase-change materials (PCM) prepared by the two methods mentioned above are 9.99 W/(m·K), 10.70 W/(m·K) and 240.06 J/g, 231.67 J/g, respectively, at EG loading by 10 wt.%, and the residual mass fraction was greater than 99% after 50 cycles of high and low temperature. In addition, due to the excellent thermal management capability of PW/EG, the operating temperature of electronic components can be stably maintained at 68–71 °C for about 15 min and the peak temperature can be reduced by at least 23 °C when the heating power of the electronic components is 10 w. These provide novel and cost-effective methods to further improve the management capability of spacecraft thermal control systems. [ABSTRACT FROM AUTHOR]

The performance of hybrid Li-ion capacitors (LICs), which aim for high energy density while maintaining high power density, declines owing to the slow kinetics of battery-type anodes. In this study, the performance of LICs was improved by directly forming a nanoporous Nb2O5 anode on a niobium (Nb) current collector through the etching of Nb via electrochemical anodization. This binder-free structure provides a large active surface and fast electron transport. In addition, the formed Nb2O5 anode had an amorphous structure with many defects, which increased the number of active sites and the conductivities of Li ions and electrons. Consequently, the amorphous nanoporous Nb2O5 (a-n-Nb2O5) anode exhibited a high specific capacity of 233 mA h g–1 at 1 A g–1 and an excellent capacity retention rate of 92% after 1000 cycles. The charge storage of the a-n-Nb2O5 anode exhibited pseudocapacitive intercalation behavior, demonstrating the rapid kinetics of the electrode. Moreover, the a-n-Nb2O5 anode exhibited an excellent energy density, maintaining a high energy density of 123.8 W kg–1 at 831 W h kg–1. [ABSTRACT FROM AUTHOR]

The quest for heightened energy efficiency is inextricably linked to advancements in energy storage and conversion technologies, wherein multifunctional catalysts play a pivotal role by mitigating the slow kinetics endemic to many catalytic reactions. The intricate synthesis and bespoke design of such catalysts, however, present notable challenges. Addressing this, the present study capitalizes on a novel dissolution manufacturing strategy to engineer self‐supporting, nanoporous multifunctional electrocatalysts, circumventing the prevalent issue of customizing catalytic functionalities upon demand. This innovative approach grants the flexibility to finely tune the incorporation of active species and metalloid binders, culminating in the creation of a self‐supporting nanoporous metal glass electrocatalyst doped with RuO2 (NPMG@RuO2) with outstanding performance in alkaline media. The catalyst showcases superior electrocatalytic activity, achieving low overpotentials of 41.50 mV for the Hydrogen Evolution Reaction and 226.0 mV for Oxygen Evolution Reaction alongside sustained stability over 620 hours.These achievements are attributed to the distinct nanoporous architecture that ensures a high density of catalytic sites and mechanical strength, bolstered by the synergistic interplay between RuO2 and Pt‐based metallic glass. The findings provide a versatile template for the development of nanoporous multifunctional catalysts, signifying a leap forward in the realm of energy conversion technologies. [ABSTRACT FROM AUTHOR]

As an efficient advanced oxidation process, the Fenton-like reaction provides a promising way toward the degradation of organic pollutants; thus, the development of a highly efficient heterogeneous catalyst is of great significance. Herein, the chemical etching behavior of Fe-Si-B metallic glass (MG) ribbons in a dilute HF solution is studied by varying the etching time. Based on this, the uniform nanoporous (NP) structures are successfully fabricated. The Fe-Si-B MG ribbons after etching for 30, 60, and 90 min still maintain an amorphous structure and possess much larger specific surface areas than untreated Fe-Si-B ribbons. The thicknesses of their nanoporous structures, with a pore size range of tens to hundreds of nanometers, are about 92.0, 180.5, and 223.4 nm, respectively. The formation of the nanoporous structure probably follows the pitting corrosion mechanism, mainly referring to the generation of corrosion pits due to the selective leaching of Si and B and pore growth and integration owing to the selective corrosion of Fe. The Fenton-like system of NPFe/H2O2 exhibits enhanced degradation performance toward methyl orange (MO), primarily due to the high intrinsic catalytic activity of the amorphous structure and the large specific surface areas of nanoporous structures, indicating the great potential application of NPFe in wastewater treatments. The mechanism analysis shows that MO degradation mainly contains two sub-processes: the heterogeneous reaction on the catalyst surface and the homogeneous reaction in MO solution, which exhibit a strong synergistic effect with excellent degradation performance. [ABSTRACT FROM AUTHOR]

Single-crystal SiC nanoporous structure has important applications in the field of micro electromechanical systems, chemical sensors and biomedical devices. However, SiC exhibits a strong chemical inertness due to the short interatomic distance and high binding energy, making it significantly challenging to fabricate nanoporous structure. Electrolytic plasma-assisted chemical etching (EPACE) based on electrochemical anodic oxidation and high-activity electrolytic plasma etching is an ideal method for SiC nanoporous structure etching. In which, the spatial distribution of electrolytic plasma has an important impact on EPACE performance, such as etching efficiency and stability. In order to analyze the impact mechanism, this paper studies EPACE in tool electrode mounting posture of vertical and horizontal types by visual observation, real-time recording of voltage-current waveforms during processing, and the morphology analysis of SiC nanoporous structure after etching. It can be found that in the vertical etching type, EPACE can proceed stably because the workpiece immersion depth is greater than the bubble accumulation thickness. However, in the horizontal etching type, bubbles accumulate seriously between the workpiece and the liquid surface, which may cause bubble cavitation and abnormal discharge, leading to damage to the etching surface. The etching current in the vertical etching type is about 1.3 times that of the horizontal etching type, indicating that the bubble mass transfer in the vertical etching type is faster and the etching impedance is smaller, which is beneficial to improve the etching efficiency and obtain a uniform nanoporous structure. Finally, a SiC nanoporous layer with a thickness of 10.6 μm was prepared at etching time t = 50 min in vertical etching type, and the etching efficiency was 212 nm/min. In addition, the prepared nanoporous structure (nanofiber) was connected to the SiC substrate, indicating that it has a good bonding strength. [ABSTRACT FROM AUTHOR]

[Display omitted] Engineering platinum-free catalysts for hydrogen evolution reaction (HER) with high activity and stability is essential for electrochemical hydrogen production. In this paper, we report the synthesis of cobalt-doped AlNi 3 /NiO (Co-AlNi 3 /NiO) electrode with three-dimensional nanoporous structure via chemical dealloying method. Density functional theory (DFT) calculations reveal that Co-AlNi 3 /NiO can accelerate water adsorption / dissociation and optimize adsorption–desorption energies of H* intermediates, thus improving the intrinsic HER activity. Both the introduction of Co and Al can efficiently ameliorate the electronic density around Ni sites of NiO and AlNi 3 , which can effectively reduce the energy barrier towards Volmer–Heyrovsky reaction and thus synergistically promote the hydrogen evolution. Benefiting from the large electrochemical active surface area, high electrical conductivity and electronic effect, the nanoporous Co-AlNi 3 /NiO catalyst exhibits remarkable HER activity with an overpotential of 73 mV at a current density of 10 mA cm−2 in alkaline condition, outperforming most of the reported non-precious metal catalysts. The nanoporous Co-AlNi 3 /NiO catalyst can operate continuously over 1000 h at high current densities with a robust stability. This work provides a new vision for the development of low-cost and efficient electrocatalysts for energy conversion applications. [ABSTRACT FROM AUTHOR]

The rise in oil spill incidents has led to a surge in environmental and ecological issues, making it crucial to create efficient oil-cleaning materials. Green approaches to address various aquatic pollution nowadays is the most important subject of environmental remediation. Among the available options, aerogel material stands out due to its low density, high porosity, and exceptional surface area, making it a remarkable choice for oil–water separation. Nonetheless, the usage of aerogels is limited by their low strength and flexibility, which hinder their application. In this study, strong alginate aerogel fibers reinforced with cotton have been synthesized with 88% porosity, 123 nm average pore size, and 0.24 g cm−3 density using a wet spinning technique followed by freeze-drying for the separation of oil/water mixtures. The morphology, chemical, and microstructural characterization of the prepared alginate aerogel fibers were performed by scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. These characterization results demonstrated the three-dimensional porous, rough structure of aerogel fibers and cotton fibers are successfully incorporated into the aerogel fiber structure. Single fiber strength tester indicated that the addition of cotton increased the strength from 2 to 16 cN of aerogel fibers but decreased the elongation. The prepared alginate aerogel fibers showed good oleophobicity underwater and excellent oil/water separation efficiency (up to 99.4%). Therefore, synthesized aerogel fiber with ease of fabrication and excellent separation of oil/water mixture is a promising candidate for commercial applications in water filtration. [ABSTRACT FROM AUTHOR]

The current work describes the algorithm for obtaining porous ammonium nitrate granules in granulation plants using devices with different fluidized bed configurations. We present brief theoretical foundations for calculating the main equipment of the granulation plant. We develop and propose the design of individual units for the sequential implementation of the main stages of ammonium nitrate modification to obtain a nanostructured porous surface layer. We assess the ammonium nitrate nanoporous structure quality and show further ways to improve the technology. Current work also pays attention to methods for ensuring the necessary specific quality indicators of porous ammonium nitrate by choosing the optimal technological mode of the unit operation and the design characteristics of the main equipment. [ABSTRACT FROM AUTHOR]

In this study, using graphite fiber cloth as the support, gold-based solid polymer electrolyte (SPE) membrane electrodes were synthesized by high-vacuum ion beam sputtering, nitrogen doping of the support, combined electrochemical dealloying, and hot-pressing technology. The application of the SPE membrane electrode to couple hydrogen evolution and liquid organic hydrogen storage is of significant importance for sustainable hydrogen energy and efficient carbon dioxide conversion. Using various characterization techniques, we systematically analyzed the phase structure, surface morphology, porous structure, and electrocatalytic performance of the membrane electrode for the hydrogenation of cyclohexene. The results indicated that doping the carbonaceous support with nitrogen (NC), doping with cerium as catalyst promoter, and combined electrochemical dealloying can all enhance the activity of the catalyst. Cerium doping provides the catalyst with oxygen vacancies for accelerated electron transfer. After combined electrochemical dealloying, AuNiCe/NC formed a three-dimensional bicontinuous porous structure. The electrochemically active surface area increased by 23.94 times, the energy consumption of catalytic cyclohexene hydrogenation decreased by 35.7%, and current efficiency and the formation rate of cyclohexane increased by 54.9% and 29.4%, respectively. [ABSTRACT FROM AUTHOR]

As an efficient advanced oxidation process, the Fenton-like reaction provides a promising way toward the degradation of organic pollutants; thus, the development of a highly efficient heterogeneous catalyst is of great significance. Herein, the chemical etching behavior of Fe-Si-B metallic glass (MG) ribbons in a dilute HF solution is studied by varying the etching time. Based on this, the uniform nanoporous (NP) structures are successfully fabricated. The Fe-Si-B MG ribbons after etching for 30, 60, and 90 min still maintain an amorphous structure and possess much larger specific surface areas than untreated Fe-Si-B ribbons. The thicknesses of their nanoporous structures, with a pore size range of tens to hundreds of nanometers, are about 92.0, 180.5, and 223.4 nm, respectively. The formation of the nanoporous structure probably follows the pitting corrosion mechanism, mainly referring to the generation of corrosion pits due to the selective leaching of Si and B and pore growth and integration owing to the selective corrosion of Fe. The Fenton-like system of NPFe/H2O2 exhibits enhanced degradation performance toward methyl orange (MO), primarily due to the high intrinsic catalytic activity of the amorphous structure and the large specific surface areas of nanoporous structures, indicating the great potential application of NPFe in wastewater treatments. The mechanism analysis shows that MO degradation mainly contains two sub-processes: the heterogeneous reaction on the catalyst surface and the homogeneous reaction in MO solution, which exhibit a strong synergistic effect with excellent degradation performance.

High quality and high efficiency cutting process is of great significance to the components manufacturing related to machinability of workpiece materials. As a typical difficult-to-machine material induced mainly by high toughness, NiTi alloy faces challenges such as high cutting force and difficult chip breaking during the cutting process. To solve these problems, this paper presents a novel surface dealloying assisted machining method, i.e., the preparation of nanoporous structures on the workpiece surface with dealloying treatment, to improve the machinability of NiTi alloy. Based on high speed in-situ imaging of material removal process, the presence of dealloyed layer leads to a segmented flow mode instead of homogeneous severe plastic deformation without dealloying treatment. The change in material removal mode is beneficial to decrease the cutting force and energy and improve the machined surface quality. The embrittlement effect of dealloyed layer inhibits material plastic flow and promotes periodic crack nucleation and propagation. An analytical model is developed to characterize the brittle crack propagation, which provides theoretical basis for explaining embrittlement effect of dealloyed layer. This work verifies the feasibility and effectiveness of the proposed method to modify the machinability of NiTi alloy and provides new ideas for the development of manufacturing processes.

The nanoporous structures obtained by the anodization of stainless steel are functional materials with various potential applications. It has been reported that nanoporous structures can be prepared by the anodization of stainless steel in an electrolyte containing fluoride ions. However, under the reported anodization conditions, the control range of the interpore distance of resulting nanoporous structures was narrow. To expand the application fields of the nanoporous structures obtained by the anodization of stainless steel, it is an important challenge to determine the anodization conditions that can control the interpore distance of nanoporous structures over a wide range. In this study, we investigated the effects of the electrolyte composition on the anodization behavior of stainless steel and the interpore distance of the resulting nanoporous structure. As a result, we found that the maximum voltage for the stable anodization of stainless steel increases when a mixture of ethylene glycol and glycerol containing NH4F is used as the electrolyte. Since the interpore distance of nanoporous structures obtained by the anodization of stainless steel is proportional to the anodization voltage, as the voltage range over which stainless steel can be anodized increased, the range of interpore distances of the nanoporous structures obtained also increased. On the basis of these results, ordered nanoporous structures with a large interpore distance (100 nm), which could not be obtained under the previously reported anodization conditions, were fabricated by the anodization of a stainless steel substrate with a depression pattern formed by Ar ion milling using an alumina mask under optimized anodization conditions. The resulting ordered nanoporous structures with controlled interpore distances are expected to be used in various devices such as capacitors and photocatalysts. [ABSTRACT FROM AUTHOR]

The current paper describes the technological foundations of the porous ammonium nitrate (PAN) convective drying stage in a multistage shelf unit operating as part of a small-sized granulation module. The work consists of two blocks: the theoretical foundations of a multistage shelf dryer operation and the study of the nanoporous PAN structure in the apparatus optimal mode of operation. The main indicator that affects the design of a gravitational shelf dryer is the required residence time of particles (granules) in the zone of contact with the drying agent. On the one hand, this time is determined by the kinetics of the drying process, and, on the other hand, by the hydrodynamic dryer operation mode, the design of the shelves (length, angle of inclination, degree of perforation) and the number of dryer stages. We present a model for calculating the "hydrodynamic" and "kinetic" residence time of PAN granules in the dryer enclosure. Paper demonstrates the features of PAN granules nanoporous structure under conditions when the "hydrodynamic" residence time of PAN granules is less than the "kinetic", equal to "kinetic" and more than "kinetic". The results of the research will be used in the development of engineering calculation methods for multistage shelf dryers and regulations for PAN production in devices with active hydrodynamic modes. [ABSTRACT FROM AUTHOR]

Current paper substantiates the possibility of obtaining porous ammonium nitrate (PAN) granules in apparatuses with intensive hydrodynamics and directional movement of the fluidized bed of granules. We developed a theoretical model for calculating the hydrodynamic performance of vortex granulators allowing to conduct experimental studies of the nanoporous structure of PAN granules. Based on this model, it is possible to determine the residence time of PAN granules in the device workspace. Together with the data on the kinetics of heat-mass exchange in the process of obtaining PAN granules, it seems possible to select the optimal modes of proper humidification and heat treatment of granules. We further confirm the optimality of these modes by the results of experimental studies of the PAN granules samples' structure. PAN granules obtained under optimal hydrodynamic conditions possess sufficient specific properties that make it possible to successfully use them as a component of ANFO industrial explosive. [ABSTRACT FROM AUTHOR]

Although TiNb2O7 is regarded as a fast‐rechargeable lithium‐ion battery (LIB) anode material, the intrinsic poor electrochemical kinetics of TiNb2O7 still dramatically impedes its development. Herein, an ionothermal synthesis‐assisted doping strategy is proposed for the preparation of a new W6+‐doped TiNb2O7 material (Ti0.95W0.05Nb2O7) with nanoporous structure (denoted as NPTWNO). The improved Li+ diffusion coefficient of NPTWNO suggests that the ionic‐liquid‐templated nanoporous architecture improves the Li+ diffusion kinetics. The density functional theory computational study reveals that the doped W6+ successfully boosts the electronic conductivity due to the narrowed conduction‐valance bandgap resulted from charge redistribution, which is reflected by the electrochemical impedance spectroscopy data. With the simultaneously enhanced Li+ diffusivity and electronic conductivity, NPTWNO achieves fast‐rechargeability in LIBs. Therefore, this work indicates the potential of ionothermal synthesis‐assisted doping strategy on energy storage materials and offers NPTWNO material with promising electrochemical performance. [ABSTRACT FROM AUTHOR]

A biosensor utilizing long-period fiber gratings (LPFG) functionalized with nanoporous coated structures was developed for the rapid detection of Staphylococcus aureus (S. aureus) bacteria. The nanoporous structure coatings on the LPFG surface facilitated specific adhesion and interaction with S. aureus, resulting in an instantaneous shift in the resonance wavelength (RW) in the transmission spectrum of the LPFG. The LPFG with nanoporous polyelectrolyte coatings exhibited an approximately seven-fold RW shift compared to the bare LPFG under the optimal experiment conditions. By tracking the RW shifts, we were able to monitor the real-time S. aureus adhesion to study the interaction process in detail. The bacterial differentiation and S. aureus specificity of the method was confirmed through a series of studies using Escherichia coli (E. coli). This nanoporous structure-enabled LPFG-based biosensor scheme holds significant promise for rapid, reliable, and low-cost detection of S. aureus for biomedical applications. [ABSTRACT FROM AUTHOR]

In this work, a highly porous cellulose/polyarylene ether nitrile (CE/PEN) membrane, bearing hierarchical beads-on-string structures, has been fabricated using regenerated cellulose derived from low-cost waste cigarette butts and PEN via the classical phase conversion method. More specifically, the sequential nucleation of CE and PEN macromolecules from dope solution results in adjustable surface segregation behavior during non-solvent induced phase separation (NIPs), leading to the formation of in-situ assembled rough beads-on-string on the external surfaces and inner pore walls of the membranes. The formation mechanism of a porous membrane with selective component distribution is investigated through thermodynamic and molecular dynamics simulations of phase separation. The resulting composite separator not only exhibits optimal physical properties, including improved mechanical strength, prominent liquid electrolyte wettability (electrolyte contact angle of 0°) and high-thermal resistance, but also demonstrates high ionic conductivity and lower interface resistance. Consequently, the CE/PEN separator enables stable lithium metal anode interface and effectively suppresses the growth of lithium dendrites. More significantly, the resulted lithium metal battery displays remarkable enhancement in capacity, cycling stability (98.6 % for 200 cycles), and rate property (101mAh/g at 10C rate). [Display omitted] • A beads-on-string structure on the external surfaces and inner pore walls of the CE/PEN membranes is founded. • CE/PEN separator possesses superior electrolyte wettability and thermal properties. • CE/PEN separator enables stable lithium metal anode interface. • CE/PEN separator displays excellent cycle and rate performance in lithium-metal battery. [ABSTRACT FROM AUTHOR]

Ferric oxide nanopores on stainless steel substrates offer a promising cathode structure for flexible supercapacitors, but their capacitance and cycling stability remain insufficient for practical use. In this study, we develop vanadium-doped nanoporous structures on stainless steel foil using a simple, cost-effective in-situ anodic oxidation method, optimizing the doping concentration. The resulting electrode exhibits a specific capacitance of 320.9 mF cm⁻2 at a current density of 1 mA cm⁻2, a 3.17-fold increase over the undoped counterpart, with 88.4 % capacitance retention after 8000 cycles. To demonstrate practical viability, we assemble a flexible hybrid supercapacitor by pairing the vanadium-doped cathode with a typical activated carbon-coated carbon cloth anode. The device exhibits a wide operating potential window of 1.8 V, a high energy density of 58.83 mWh·cm⁻³, and a power density of 0.5 W cm⁻³, alongside robust bending tolerance. The enhanced performance is attributed to an increased number of redox reaction sites and reduced internal resistance, as confirmed through both experimental and theoretical analysis. These findings highlight the potential of vanadium-doped nanoporous structures for use in high-performance, flexible, and cost-effective supercapacitors. [Display omitted] • In-situ vanadium-doping was done on an anodic oxidized stainless steel substrate. • The composite showed more than 3 times capacitance increment than the undoped one. • An excellent 88.4 % capacitance retention over 8000 cycles was achieved. • Flexible supercapacitor with energy density of 58.83 mWh·cm−3 at 0.5 W cm−3. [ABSTRACT FROM AUTHOR]

Electrocatalytic CO 2 reduction into high-value multicarbon products offers a sustainable approach to closing the anthropogenic carbon cycle and contributing to carbon neutrality, particularly when renewable electricity is used to power the reaction. However, the lack of efficient and durable electrocatalysts with high selectivity for multicarbons severely hinders the practical application of this promising technology. Herein, a nanoporous defective Au 1 Cu single-atom alloy (De-Au 1 Cu SAA) catalyst is developed through facile low-temperature thermal reduction in hydrogen and a subsequent dealloying process, which shows high selectivity toward ethylene (C 2 H 4 ), with a Faradaic efficiency of 52% at the current density of 252 mA cm -2 under a potential of -1.1 V versus reversible hydrogen electrode (RHE). In situ spectroscopy measurements and density functional theory (DFT) calculations reveal that the high C 2 H 4 product selectivity results from the synergistic effect between Au single atoms and defective Cu sites on the surface of catalysts, where Au single atoms promote *CO generation and Cu defects stabilize the key intermediate *OCCO, which altogether enhances C-C coupling kinetics. This work provides important insights into the catalyst design for electrochemical CO 2 reduction to multicarbon products.

Abstract Objective Various surface modification techniques that can further improve the function and usability of stainless steel as a medical device have been reported. In the present study, the physical and biological properties of nanoporous stainless steel as well as its usefulness for drug delivery were assessed. Methods The specimen was prepared with a circular disk shape (15 mm in diameter and 1 mm in thickness). The disk was subjected to electropolishing at a constant voltage of 20 V and 10 A for 10 min in an acidic environment (50% H2SO4). Everolimus (EVL) was used as a testing drug for drug-loading capacity of the material surface and release kinetics. The physiobiological properties of the material were assessed using platelet adhesion, and smooth muscle cell (SMC) adhesion, migration, and proliferation assays. Results The surface roughness of the postpolishing group was greater than that of the nonpolishing group. Platelet adhesion and SMC adhesion and migration were inhibited in the postpolishing group compared to those in the prepolishing group. In the postpolishing group, the total amount of EVL on the surface (i.e., drug storage rate) was higher and the drug release rate was lower, with half the amount of the EVL released within 4 days compared with only 1 day for that of the prepolishing group. Conclusion Taken together, this stainless steel with a nanoporous surface could be used as a medical device for controlling cellular responses and carrying drugs.

Using tetraethoxysilane (TEOS) as a precursor, silica aerogels were synthesized via the sol-gel polymerization followed by supercritical drying process. During the polymerization period, N, N-dimethylformamide (DMF), acting as a chemical additive for the structure control, was introduced in the hydrolysis step and condensation step, respectively. As a result, the nanopore volumes for the pores smaller than 100 nm were up to 6.0 cm3/g and 5.7 cm3/g for the samples that produced with DMF addition in the hydrolysis step and condensation step, while the value for the sample without DMF was only 4.6 cm3/g. Besides, the sample with DMF addition in the condensation step possessed more uniform pore size distribution while compared with that with DMF addition in the hydrolysis step. DMF can provide a shielding layer around the colloid particles through hydrogen bonds, inhibiting the aggregation of colloid particles and the enlarging of pore sizes.

To effectively reduce building energy consumption and enhance energy efficiency of structures, this study synthesized calcium phosphate (CaP) bone cement microspheres with nanoporous structure via hydrothermal methods and then prepared CaP microsphere cement mortar. Through mechanical properties test, microstructural characterization, and software simulation, the impacts of CaP microspheres on the mechanical and thermal insulation properties of cement mortar were investigated. The results demonstrated that the incorporation of CaP porous microspheres not only enhanced the mechanical interlocking between the CaP porous microspheres and cement mortar but also increased the specific surface area within the cement, which led to an increase in mechanical and thermal insulation properties of the cement mortar. After seven days of curing, the 0.05 % CaP cement mortar exhibited increases of 14.6 % in flexural strength and 17.75 % in compressive strength compared to the reference cement. At 28 days, these strengths increased by 6.73 % and 11.51 %, respectively. Additionally, thermal conductivity measurements at 20°C, 25°C, and 30°C showed reductions of 19.3 %, 19.6 %, and 18.5 %, respectively. This study introduces innovative cement additive approaches for enhancing cement-base building materials. [Display omitted] • Developed a nanoporous calcium phosphate bone cement microsphere additive. • Devised a simple, low-energy synthesis method. • Enhanced both the mechanical and thermal insulation properties of cement mortar. • Offered new insights for energy-efficient design in cement-based building materials. [ABSTRACT FROM AUTHOR]

• The self-supporting hierarchical nanoporous CoCrFeNiAl 1.5 high entropy alloy ribbons were prepared by one step phase dealloying. • Unique hierarchical nanoporous structure possess high specific surface area and provide reaction channels for the transport of reactant molecule and ions. • The Co, Cr, Fe oxides in fine nanopores forming as reactive center provide sufficient active sites for the reduction reaction of H 2 O 2 molecules. • NPCCF-1.5 with visible Fe-Cr GB increase H 2 O 2 molecule diffusion coefficient and speed electron transfer, which is benefit to accelerate reactant process. High entropy alloys (HEAs) are promising materials in electrocatalytic fields due to inherent compositional designability and structural diversity. Herein, unique hierarchical CoCrFeNiAl 1.5 high entropy nanoporous structure (NPCCF-1.5) with two-level pores of ∼580 nm and ∼13 nm in size, and visible inherited Fe-Cr(Co) rich disordered BCC phase grain boundary (Fe-Cr(Co) GB) was constructed from CoCrFeNiAl 1.5 HEA ribbons by preferential dissolution of the Al-Ni rich ordered BCC phase (B2). The self-supporting NPCCF-1.5 electrodes as H 2 O 2 sensor exhibit an ultra-high sensitivity of 510.4 μA mM-1 cm-2, a wide linear detection range up to 49.95 mM and low limit of quantitation of 4 μM (S/N ≥ 3), along with excellent anti-interference ability. The hierarchical nanoporous structure supports mass transferring channels and large amounts of active sites for catalytic reaction, and inherited Fe-Cr(Co) GB facilitates reactive molecule/electron transfer to the active sites of the fine pores composed of Co, Cr, and Fe oxides. The strategy that utilizes the inherited microstructural advantage of HEAs provides a reliable route for the development of low-cost, high-performance porous electrocatalysts. [Display omitted] [ABSTRACT FROM AUTHOR]

This work presents a unique electrocatalyst of nanoporous AuPd alloy electrocatalyst. By utilizing the abundant active sites from porous structure and the synergia between Au and Pd, we achieve superior ENRR enhancement with high ammonia yield of 43.6 μg·h−1·cm−2 and Faradaic efficiency of 43.8%. [Display omitted] • Unique porous AuPd alloy nanostructures (pAuPdNs) have been prepared with Pd homogeneously distributed throughout the entire nanostructure and Au concentrated in the core. • The designed pAuPdNs structure achieves high ammonia production of 43.6 μg·h−1·cm−2 and superior catalytic efficiency of 43.8 %. • PAuPdNs structure shows excellent selectivity (95%), as well as long-time and multi-cyclic stability, which prove the suitably promising application for ammonia production. In industry, production of ammonia mainly relies on the intensive Haber-Bosch process, but it consumes high energy with low efficiency and generates a large number of green-house gases. Electrocatalytic nitrogen reduction reaction (ENRR), as an alternative method for fixing N 2 under ambient conditions, provides a feasible strategy for sustainable development of N 2 cycle storage and utilization of renewable energy. However, traditional nanocatalysts exhibit extremely poor ENRR performance due to low activity of the solid structure and intense hydrogen evolution reactions of single component. Herein, we design and prepare porous gold–palladium nanoalloys (pAuPdNs), which effectively enhance ENRR by the excellent catalytic activity of Au and the significant N 2 fixation ability of Pd, as well as the nanoporous structure and synergistic effect between alloy components. The electrochemical results show the NH 3 yield of the catalyst is as high as 43.6 μg·h−1·cm−2, and Faradaic efficiency reaches 43.8%, which are superior to the performances of most reported water-based ENRR electrocatalysts. Besides, the selectivity of 95% and stability also exhibit enhancement than numerous reported researches. As compared with solid alloy and porous Au or Pd structures, the superiority of pAuPdNs states the influence of alloying and porous structure. Hence pAuPdNs are proved to be the efficient, stable, and promising electrocatalysts for N 2 reduction reaction at ambient temperature and atmospheric pressure. [ABSTRACT FROM AUTHOR]

Current paper is devoted to the study of formation process of a nanoporous structure in porous ammonium nitrate granules during their humidification and heat treatment in vortex devices. We briefly present the main methods for porous ammonium nitrate granules formation. We demonstrate that it is necessary to control the process of nanoporous structure formation by varying different technological parameters. We present a brief description of a method for producing porous ammonium nitrate granules with nanoporous structure in vortex granulators based on ordinary ammonium nitrate granules. The nanoporous structure of porous ammonium nitrate granules is investigated under various technological parameters of the modification process. We provide porous ammonium nitrate quality indicators and propose optimal parameters for its production. [ABSTRACT FROM AUTHOR]

The fabrication of electrocatalysts with high activity and acid stability for acidic oxygen evolution reaction (OER) is an urgent need, yet extremely challenging. Here, we report the design and successful fabrication of a high performance self-supported cogwheel arrays-like nanoporous IrxRu1−xO2 catalyst with abundant atomic steps for acidic OER using a facile alloy-spinning-electrochemical activation method that allows large-scale fabrication. The obtained IrxRu1−xO2 catalysts merely need overpotentials of 211 and 295 mV to deliver catalytic current densities of 10 and 300 mA·cm−2 in 0.5 M H2SO4, respectively, and can sustain constant OER electrolysis for at least 140 h at a high current density of 300 mA·cm−2. Further density functional theory (DFT) calculations uncover that such high intrinsic activities mainly originate from the largely exposed high-index atomic step planes, which markedly lower the limiting potential of the rate-determining step (RDS) of OER. These findings provide an insight into the exploration of high performance electrocatalysts, and open up an avenue for further developing the state-of-the-art Ir and/or Ru-based catalysts for large-scale practical applications. [ABSTRACT FROM AUTHOR]

Hierarchically porous carbon aerogels (CAs) were synthesized by following a green, facile preparation route involving ice-templating and lyophilization followed by carbonization. For the first time, we report CAs prepared with a cooling rate of 7.5 K/min, demonstrating a very high specific surface area (SSA) of 1260 m2 g–1 without any physical or chemical activation steps, and the electrode prepared using the latter aerogel showed superior electrochemical performance with a specific capacitance of 410 F g–1 at 2 m V s–1 with a cyclic stability of 94% after 4500 charge–discharge cycles. The effects of the ice-templating cooling rate and the solid content of lignin and cellulose nanofibers (CNFs) in the suspension on the structure and electrochemical performance of the CAs were investigated. The ice-templating process and the cooling rate were found to have a large effect on the generation of the nanoporous structure and the specific surface area of carbon aerogels, while the solid content of the lignin-nanocellulose suspension showed negligible effects. When assembled as a supercapacitor (SC), a remarkable specific capacitance of 240 F g–1 at 0.1 A g–1 was achieved. The relaxation time constant for the prepared SC was 1.3 s, which shows the fast response of these SCs. In addition, an energy density of 4.3 Wh kg–1 was also obtained at a power density of 500 W kg–1. Thus, this study opens new perspectives for the preparation of green, environment-friendly, free-standing, high-performance CA electrodes for future energy storage applications. [ABSTRACT FROM AUTHOR]

Heavy silicon-doping in GaN generally causes a rough surface and saturated conductivity, while heavily silicon-doped n++-AlGaN with ≤5% aluminum can maintain an atomically flat surface and exhibit enhanced conductivity. Given this major advantage, we propose using multiple pairs of heavily silicon-doped n++-Al0.01Ga0.99N and undoped GaN instead of widely used multiple pairs of heavily silicon-doped n++-GaN and undoped GaN for the fabrication of a lattice-matched distributed Bragg reflector (DBR) by using an electrochemical (EC) etching technique, where the lattice mismatch between Al0.01Ga0.99N and GaN can be safely ignored. By means of using the EC etching technique, the n++-layers can be converted into nanoporous (NP) layers whilst the undoped GaN remains intact, leading to a significantly high contrast in refractive index between NP-layer and undoped GaN and thus forming a DBR. Our work demonstrates that the NP-Al0.01Ga0.99N/undoped GaN-based DBR exhibits a much smoother surface, enhanced reflectivity and a wider stopband than the NP-GaN/undoped GaN-based DBR. Furthermore, the NP-Al0.01Ga0.99N/undoped GaN-based DBR sample with a large size (up to 1 mm in width) can be obtained, while a standard NP-GaN/undoped GaN-based DBR sample obtained is typically on a scale of a few 100 μm in width. Finally, a series of DBR structures with high performance, ranging from blue to dark yellow, was demonstrated by using multiple pairs of n++-Al0.01Ga0.99N and undoped GaN. [ABSTRACT FROM AUTHOR]

An efficient heterogeneous catalytic system for the N‐formylation of amines using CO2 as a sustainable C1 source was developed using unsupported nanoporous palladium (PdNPore). The PdNPore‐catalyzed N‐formylation of amines and CO2 with hydrosilane proceeded smoothly under mild reaction conditions to yield formamides in satisfactory to excellent yields. Various synthetically useful functional groups, such as halogen, hydroxyl, allyl, and cyano groups, remained intact during the N‐formylation of amines. No palladium leached from PdNPore during the hydrogenation reaction. Moreover, the catalyst was easily recovered and reused without any loss of catalytic activity. This study is the first to demonstrate that PdNPore catalyzed CO2 conversion to form C−N bond, which enriches the reaction types of CO2 conversion catalyzed by PdNPore catalyst. [ABSTRACT FROM AUTHOR]

The article studies the final drying stage in the porous ammonium nitrate (PAN) production. Based on the analysis of the ammonium nitrate, authors propose to improve the scheme for the PAN production by introducing the final drying stage after humidification and heat treatment of PAN in a vortex granulator. The analysis of literature proposes a new design for the drying unit—a gravitational shelf dryer with vertical sectioning of the workspace. There is a theoretical and experimental description of the PAN granule heating and dehydration processes in a dryer. The studying results of the PAN granule surface morphology after the final drying stage are presented. Comparative indicators of the quality of PAN granules, obtained with using and without using the final drying stage, are given. [ABSTRACT FROM AUTHOR]

The article describes a new technology for the formation of nanoporous layers on the ammonium nitrate granule as a component of an industrial explosive. The main methods of porous ammonium nitrate (PAN) production are defined. The authors substantiate the effective implementation of the combined method of humidification and heat treatment. It is proposed to use a new granulator (vortex granulator) for the PAN obtaining method using humidification followed by heat treatment. The necessity to form a developed network of nanopores on the PAN granule surface is proved. A theoretical model describing the kinetics of humidifier's film applying to the granule surface for subsequent drying and the nanoporous coating formation is presented. The phase composition of various samples of ammonium nitrate is studied. It is shown that all PAN samples do not undergo chemical transformations. The morphology of the PAN granule surface is studied to determine the porous structure nature. The studying results of the effect made by the type of humidifier, the heat treatment time and the number of heat treatment cycles on the PAN quality are demonstrated. [ABSTRACT FROM AUTHOR]

Developing an efficient and simple heterogeneous catalytic system for CO2 conversion into formic acid (FA) is a vibrant research area because FA is recognized as a liquid organic hydrogen carrier. On the basis of our previous work on unsupported nanoporous palladium‐catalyzed hydrogenation proceeding through a Pd‐hydride intermediate, we report herein four types of PdNPore catalysts for the CO2 hydrogenation. The PdNPore‐1 catalyst exhibited high catalytic activity for CO2 hydrogenation into formate and obtained a yield of 86 % at 80 °C under H2 (1.0 MPa) and CO2 (1.5 MPa) with 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) as a base in acetonitrile. Moreover, the catalyst was easily recovered and reused without any loss of catalytic activity. Sodium bicarbonate could also be hydrogenated using the PdNPore‐1 catalyst. [ABSTRACT FROM AUTHOR]

An innovative low-cost method of aluminium surface treatment to obtain stable superhydrophobic properties is presented. An aluminium anodising method was combined with surface abrasive blasting as a mechanical pre-treatment to obtain combined microscale roughness and nonporous surface structure. The produced layer was impregnated with fatty acid. The surface morphology was examined by SEM and optical microscopy. The influence of the process parameters on the wettability of the aluminium surface was investigated. The features of the prepared samples were tested in terms of the durability of the coating. The test results confirm the stable superhydrophobic properties of the obtained layers with contact angle larger than 150° and roll-off angle less than 5°. [ABSTRACT FROM AUTHOR]

Three-dimensional gold and its alloyed nanoporous structures possess high surface areas and strong local electric fields, rendering them ideal substrates for plasmonic molecular detection. Despite enhancing plasmonic properties and altering molecular interactions, the effect of alloy composition on molecular detection capability has not yet been explored. Here, we report molecular interactions between nanoporous gold alloys and charged molecules by controlling the alloy composition. We demonstrate enhanced adsorption of negatively charged molecules onto the alloy surface due to positively charged gold atoms and a shifted d-band center through charge transfer between gold and other metals. Despite similar EM field intensities, nanoporous gold with silver (Au/Ag) achieves SERS enhancement factors (EF) up to 6 orders of magnitude higher than those of other alloys for negatively charged molecules. Finally, nanoporous Au/Ag detects amyloid-beta at concentrations as low as approximately 1 fM, with SERS EF up to 10 orders of magnitude higher than that of a monolayer of Au nanoparticles.

A novel fabrication method of uniform porous structures on the glass surface is proposed. The hydrofluoric acid fog formed by air-jet atomization etches the glass surface to fabricate nanoporous structure (NPS) on glass surface. This NPS shows the enhanced average light transmittance of approximately 92.9% and the superhydrophilic property with a contact angle less than 1° which presents an excellent anti-fog property. Passivated by fluorosilane, the NPS shows nearly the superhydrophobic property with a contact angle of 141.2°. This fabrication method has shown promising application prospects due to its simplicity, low cost and efficiency, which can be easily applied to large-scale industrial production.

Bicontinuous nanoporous metallic glasses (MG) synergize the outstanding properties of MGs and open-cell nanoporous materials. The low-density and high-specific-surface-area of bicontinuous nanoporous structures have the potential to enhance the applicability of MGs in catalysis, sensors, and lightweight structural designs. Here, we report molecular dynamics simulations of tensile loading deformation and failure of bicontinuous nanoporous Cu 64 Zr 36 MG with 55% porosity and 4.4 nm ligament size. Results indicate an anomalous mechanical behavior featuring delocalized plastic deformation preceding ductile failure. The deformation follows two mechanisms: i) Necking of ligaments aligned with the loading direction and ii) progressive alignment of randomly oriented ligaments. Failure occurs at 0.16 strain, following massive rupture of ligaments. This work indicates that a bicontinuous nanoporous design is able to effectively delocalize strain localization in a MG due to a combination of size effect on the ductility of MGs resulting in nano ligaments necking and progressive asynchronous alignment of ligaments. Image, graphical abstract [ABSTRACT FROM AUTHOR]