Porous Frame Research Articles

MOF-derived CoCu-N-doped porous carbon frame electrocatalyst for high performance zinc-air battery

MOF-derived CoCu-N-doped porous carbon frame electrocatalyst for high performance zinc-air battery

Porous Organic Frame Materials for Adsorption and Removal of Pesticide Contaminants: A Review

Porous Organic Frame Materials for Adsorption and Removal of Pesticide Contaminants: A Review

A Recyclable Energy Storage Wood Composite with Photothermal Conversion Properties for Regulating Building Temperature

AbstractAddressing the challenges of energy storage liquid leakage and long‐term stability in energy storage is crucial for achieving sustainable energy efficiency. In this study, polymethyl methacrylate (PMMA) is innovatively employed as an encapsulation film on the surface of the wood‐based phase change material, resulting in a recyclable wood‐based composite energy storage material (PPW). A novel energy storage liquid (PCMs) composed of lauric acid (LA), capric acid (CA), and polyethylene glycol (PEG) is immersed in the pretreated porous wood frame through vacuum impregnation. The PCMs imparted a phase change temperature of 21.0 °C, which is close to human comfort levels, and a high energy storage efficiency of 31.6 J g−1 to the PPW. Additionally, the PCMs provided the PPW with a photothermal conversion efficiency of 29.3%. Even after 200 freeze‐thaw cycles, the energy storage properties of the PPW remained nearly unchanged. Therefore, utilizing PMMA as an effective encapsulation material is a viable approach to prevent leakage of the phase change solution and enhance the recyclability of the PPW. Furthermore, the transparency of PMMA preserves the natural appearance of the wood, thereby broadening the application potential of PPW in residential buildings, thermal energy storage, and solar thermal conversion systems.

Heat Transportation of 3D Chemically Reactive Flow of Jeffrey Nanofluid over a Porous Frame with Variable Thermal Conductivity

Nanofluids with variable thermal conductivity can potentially bring about a transformative impact in various industries. They offer adaptive and efficient heat transfer solutions that can adjust to changing conditions and specific requirements. The insertion of nanoparticles into the base fluid significantly changes its properties, affecting thermal conductivity and viscosity. The primary objective of this paper is to analyze the heat transfer rate and three-dimensional bio-convective flow of a non-Newtonian Jeffrey nanofluid across a porous surface with variable thermal conductivity. The investigation also considers the impacts of thermophoresis, Brownian motion, and the Lorentz force. The combine impact of thermal radiation and motile microbes also incorporated in the current study. To model these phenomena, we employ the boundary layer approximation to derive a system of partial differential equations (PDEs). These PDEs are subsequently simplified into more manageable ordinary differential equations (ODEs) using the similarity variables. The numerical analysis is performed via the finite difference approach, which consists of a three-stage Lobatto scheme using MATLAB package. Additionally, important engineering parameters under different constraints-like skin friction, Nusselt number, and Sherwood number—are given in a thorough manner using tabular and graphical representations. The results of this study demonstrate significant enhancements in various aspects, including thermophoresis, Brownian motion, and thermal boundary layer thickness are demonstrated through graphically and in the form of tables. As the thermal radiation parameter increases, the temperature profile rises accordingly. This enhancement in the temperature profile is directly attributable to the higher value of the radiation parameter, which results in a physical increase in temperature. These improvements are attributed to a reduction in viscous forces and an increase in the Brownian diffusion coefficient. This research advances the understanding of non-Newtonian thermally radiative flow with variable thermal conductivity, elucidating the complex behavior of such fluids and providing valuable insights for engineering applications.

Dual Eu3+ and Er3+ doping in ZnO nanoporous 2D frameworks for tuning photocatalytic activity, linear and non-linear optical response

Recent days, the greater attention of research materials are focusing on the porous nano frame structure due to their distinctive properties and high photocatalytic activity. The porous defective materials revealed a significant role in numerous research fields like sensors, catalysts, energy production, magnetic memory storage, bio medical etc. In our work, pure ZnO and 4f shell shielded rare earth metals doped ZnO metal oxide nanomaterials attributed in the photocatalytic dye degradation, non-linear optical and magnetic properties. We were synthesized pure ZnO and ZnO0.1–2xEuxErxHMT0.1–2x (2x = 0.025,0.05,0.075, 0.010 wt%) nanoparticles using a straightforward hydrothermal route. The hexagonal wurtzite structure of ZnO and Eu:Er-doped ZnO (Eu:Er@ZnO) exhibited by PXRD, and the optical bandgap (Eg) range from 3.14 eV to 3.18 eV was determined by Tauc relation (αhγ)2 = 0. The porous nanoplate morphology of as-synthesized materials revealed by HR-SEM and HR-TEM techniques. All synthesized materials exposed weak ferromagnetic property nature by VSM studies. Among all the synthesized materials, the 0.0025 wt% Eu:Er@ZnO nanoparticles exhibited porous nanoplate structures capable of catalyzing the breakdown of reactive black 5 (RB5) dye, achieving a photocatalytic activity of 93.2 % after 65 min of UV light exposure. The dopant concentration significantly influenced this photocatalytic activity, with lower concentrations showing enhanced performance, particularly in acidic conditions. Moreover, all synthesized porous nano-plate materials followed pseudo-first-order kinetics. Additionally, the Z-scan technique was employed to assess the nonlinear optical properties of the synthesized materials using Q-switched nanosecond Nd laser pulses at 532 nm wavelength. The open-aperture Z-scan revealed reverse saturable absorption (RSA) in all samples. The Eu:Er@ZnO porous nano-plates exhibited promising nonlinear absorption characteristics, with a higher nonlinear absorption coefficient ranging from 5.21 to 7.84 × 10−11 m/W and a lower optical limiting threshold between 0.87 and 0.95 × 1012 W/m2.

Wood Sponge for Oil-Water Separation.

In addition to filtering some sediments, hydrophobic wood sponges can also absorb many organic solvents, particularly crude oil. The leakage of crude oil poses a serious threat to the marine ecosystem, and oil mixed with water also generates great danger for its use. From the perspective of low cost and high performance, wood sponges exhibit great potential for dealing with crude oil pollution. Wood sponge is a renewable material. With a highly oriented layered structure and a highly compressible three-dimensional porous frame, wood sponges are extremely hydrophobic, making them ideal for oil-water separation. Currently, the most common approach for creating wood sponge is to first destroy the wood cell wall to obtain a porous-oriented layered structure and then enhance the oil-water separation ability via superhydrophobic treatment. Wood sponge prepared using various experimental methods and different natural woods exhibits distinctive properties in regards to robustness, compressibility, fatigue resistance, and oil absorption ability. As an aerogel material, wood sponge offers multi-action (absorption, filtration) and reusable oil-water separation functions. This paper introduces the advantages of the use of wood sponge for oil-water separation. The physical and chemical properties of wood sponge and its mechanism of adsorbing crude oil are explained. The synthesis method and the properties are discussed. Finally, the use of wood sponge is summarized and prospected.

Theoretical study on the luminescence mechanism of AIEgens based HOFs adsorbing small molecules

The diversity and reversibility of non-covalent interactions give hydrogen-bonded organic frameworks (HOFs) excellent gas adsorption and separation performance. Here we designed and synthesized HOFs based on aggregation-induced emission luminogens (AIEgens) to visualize the adsorption process of HOFs. We focused on the SQ system and its solvated SQ frameworks by different solvent conditions, employing the thermal vibration correlation function rate formalism coupled hybrid quantum mechanics/molecular mechanics protocol, to elucidate the relation between crystal structure and luminescent properties, as well as the specific adsorption ability of porous SQ HOF crystals on acetylene gas. It is found that compare to SQ crystal, the SQ symmetry in cocrystals are improved, and SQ-DCM cocrystal has the best symmetry. The absorption spectra of five SQ-based crystals are close to each other, and their emission spectra blueshifted from 540 nm of SQ, to 509 nm, 508 nm, 507 nm of SQ-EA, SQ-ACN, SQ-DCM, and then to 495 nm of SQ-TOL, consistent with experimental results. The kic of solvated cocrystals are about 1∼2 orders of magnitude smaller than that of non-solvated crystal SQ, resulting in significantly higher Φexp of solvated cocrystals than that of un-solvated one. DCM with small volume and C2v point group is more suitable for SQ crystal channel, indicating that small free region and shape matching are the key factors affecting the reversibility of crystallization of porous frames during solvent transport. Finally, the volume of the adsorbed gas C2H2 which is close to DCM, is more easily adsorbed by SQ framework. Our study offers theoretical insights into the design of porous crystals for gas adsorption and separation applications.

РАЗРАБОТКА СПОСОБА ПРОПИТКИ УГЛЕГРАФИТА ВОДНЫМ РАСТВОРОМ ЭЛЕКТРОЛИТА МЕДНЕНИЯ

The article is devoted to the development of a method of impregnation of porous carbon graphite frame with aqueous solution of copper electrolyte. It is shown that at impregnation under atmospheric pressure the percentage of filling of open pores amounted to 9.7% for 2 hours of soaking, while the impact of ultrasound allowed to achieve filling of 57.2% for the same time. Carbon graphite billets aged in electrolyte for 24 hours showed 84% open pore filling, and the application of ultrasound allowed filling 98.3% of open pores in 8 hours of soaking.

Prediction of reservoir properties and fluids using rock physics techniques in the Rio Del Rey Basin, Cameroon

The application of rock physics modeling has been a breakthrough in oil and gas industry and has greatly managed exploration and interpretation risk. In the Rio del Rey Basin, the rock physics method was used to ascertain the reservoir's characteristics and relate them to the elastic characteristics. Using conventional techniques to connect to the elastic properties and assess various rock physics diagnostics, the estimated petrophysical parameters were water saturations, porosity, and shale volume. By connecting the saturated bulk modulus to its porosity, the bulk modulus of the porous frame, the bulk modulus of the mineral matrix, and the bulk modulus of the pore filling fluids, the Gassmann fluid replacement modeling was used to simulate various fluid scenarios. Finally, an evaluation was conducted on rock physics boundaries and cement models. The reservoirs are rated as extremely good based on the results. The rock physics model generated showed the friable sand model is a suitable model for the said basin and the rock physics bounds that were evaluated indicated that the sediments are deposited below the critical porosity and less compacted thereby depicting a soft sand model. Conventional petrophysical study would not be able to reveal the clustering of the gas sands from the brine sand and the shale zone in connection to the geologic trend as demonstrated by the rock physics template. The anticipated model will be useful to extrapolate the study to other sedimentary basins in Cameroon and estimate porosity from the impedance acquired from seismic data throughout the basin.

A La-MOF as multi-responsive fluorescence sensor for Fe3+, PO43− and p‑Nitroaniline with high sensitivity and selectivity

Excessive emissions of Fe3+, PO43−, and p-Nitroaniline in the environment pose a major threat to human health and the earth ecology. Hence, a rapid and effective detection method for these pollutants is urgently needed. Here, three kinds of three-dimensional porous lanthanide metal-organic frame materials (Ln-MOFs) have been synthesized by hydrothermal method, namely {[Ln3(NTB)3(bib)0.5(H2O)2]•nH2O}n [H3NTB = Nitrilotrisbenzoic acid, bib = 1,4-bis(1-Imidazoly)benzene, Ln = La(Ⅰ), Ce(Ⅱ), Pr(Ⅲ)]. By single crystal X-ray diffraction analysis, Ⅰ-Ⅲ are homogeneous compounds with monoclinic crystal system and P21/c space group. Peculiarly, La-MOF (Ⅰ) is an excellent multi-response luminescence sensor, which can simultaneously detect Fe3+, PO43− and p-Nitroaniline (LOD values are 1.29 × 10−6 M, 1.59 × 10−6 M, 1.32 × 10−6 M, respectively) with high selectivity, low detection limit and good anti-interference ability. It is a rare multifunctional fluorescence sensor for Fe3+, PO43− and p-Nitroaniline. In addition, La-MOF (I) has excellent chemical and thermal stability, and it can be stable in aqueous solutions with pH = 2–12 and below 240℃, which indicates that La-MOF (I) has the potential to be applied in practical complex environments. The possible mechanisms in the fluorescence sensing process are explored by X-ray powder diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), UV–vis spectroscopy and density functional theory (DFT).

Porous Silicone Rubber Composite Supported 1,4-Diphenylethynyl Benzene for Hydrogen Absorption with Pd/C Catalyst.

Hydrogen is a dangerous gas as it reacts very easily with oxygen and may explode; therefore, the accumulation of hydrogen in confined spaces is a safety hazard. Composites consisting of unsaturated polymers and catalysts are a common getter, where the commonly used polymer is 1,4- diphenylethynyl benzene (DEB). Silicone rubber (SR) is a good carrier for hydrogen-absorbing materials due to its excellent chemical stability and gas permeability. In this work, polysiloxane, water, and a emulsifier are ultrasonically injected into a uniform emulsion, and the hydrogen getter DEB-Pd/C (Palladium on carbon) is then added. Under the catalysis of platinum (Pt), the cross-linking agent undergoes a hydrosilylation reaction to cross-link polysiloxane in emulsion to form silicone rubber. Then, the water was removed by freeze-drying, and the loss of water constructed a porous frame structure for silicone rubber, thus obtaining porous silicone rubber. The difference in hydrogen absorption performance between porous silicone rubber and ordinary silicone rubber was compared. It was found that, with the increase in water in the emulsion, the porous frame of silicone rubber was gradually improved, and the hydrogen absorption performance was improved by 243.4% at the highest, almost reaching the theoretical saturated hydrogen absorption capacity. Porous silicone rubber was prepared by emulsion mixing, which provided a new idea for further improving the hydrogen absorption performance of silicone rubber.

Static analysis of functionally graded porous beam-column frames by the complementary functions method

In this paper, an efficient and accurate numerical approach is implemented to examine the static behavior of Functionally Graded Porous (FGP) planar frames for the first time. The symmetric material constitutive relationship (SMCR), monotonic material constitutive relationships (MMCR), and uniform material constitutive relationship (UMCR) models are used to define the gradation of porosity along the thickness direction. The effects of porosity coefficient and material porosity distribution type on the static behavior of the FGP frames are investigated in detail. A direct relation between porosity coefficient and nodal deformations is observed.The effect of shear deformation is considered in the governing equations based on the Timoshenko Beam Theory (TBT). Within the scope of the presented procedure, fifth-order Runge-Kutta (RK5) algorithm is applied in the solution of the initial value problems. Imposing the rigidity matrix-based Complementary Functions Method (CFM) on the static analysis of the FGP planar frames is the novelty of this research. The results of the suggested approach are verified with the those of the finite element method (FEM), and those of the available literature. It has been carried out that type of the porosity distribution and porosity gradient index have an important impact on the response of FGP planar frames. By increasing the porosity coefficient, the displacement values of the frames made of UMCR and MMCR porosity distribution are affected more than those of the UMCR distributions. It can be noted that the SMCR can be preferred for designing the FGP beam-column structure as the minimum deformation values are obtained.

PHYSICO-CHEMICAL PROCESSES OF ALKALINE ACTIVATION OF SILICA DURING HEAT TREATMENT IN THE SIO2-NaOH-H2O SYSTEM

The physicochemical processes during alkaline activation of the SiO2-NaOH-H2O system with crystalline silica have been investigated. The studies were carried out using thermogravimetric, X-ray phase analysis methods and IR spectroscopy data. Compositions with different silicate modulus (SiO2/Na2O 4-7), the amount of the introduced silica fume (10-30%) in substitution of marshalite and the concentration of sodium hydroxide solution (30-60 wt.%) are considered. According to the results of the study, the reactions of interaction of the components and a model of phase transformations in the composition when it is heated to 850 °C are proposed. At the stage of interaction of the components (30-130 °C), hydration processes occur with the formation of sodium hydrosilicate Na2SiO3(OH), with on the surface of which a layer of crystallohydrate water and a water layer to be formed without formation of free water. When the composition is heated to temperatures of 130-300 °С the water layer and then the crystallohydrate water are removed. The removed water interacts with unreacted silica and forms hydrated forms of silica. Upon further heating to temperatures of 310-800 °C, OH groups are removed from sodium hydrosilicates and hydrated forms of silica and it turns into anhydrous silicates. Heating the composition to 850 °C leads to the formation of a pyroplastic mass from a eutectic melt (Na2O·2SiO2–SiO2) and residual silica. The two-stage mechanism of formation of a porous frame is established at the stage of decomposition of sodium hydrosilicate crystallohydrates (80-200 °C) and at the stage of melt foaming at high temperatures (790-850 °C). Foaming occurs due to the removal of water vapor (80-200 °C) and the expansion of the volume of gases (790-850 °C) in the porous structure formed at the first stage of foaming. The developed compound of the high-modulus composition (SiO2/Na2O 5,7) is a basis to obtain a porous glass composite using a two-stage alkaline technology with the introduction of additional oxides that increase chemical resistance. The composition includes the following components, wt.%: marshalite – 50, silica fume – 23, sodium hydroxide – 16, water – 11.

Solar Desalination with Monolithic Foams Containing a Combination of Graphite and SnSe Featured with a Hierarchical Structure and Bimodal Pores for Spontaneous Salt Rejection

The increasing interest in solar water evaporation technology is due to its potential to replace conventional desalination systems. In this study, we suggest a new solar desalination system that has a hierarchical photothermal structure and is structurally monolithic. The overall membrane is made up of a macroscale porous melamine foam frame that acts as a porous insulator and a mass transfer layer. The mass transfer layer is designed with a bimodal porous structure of melamine foam, with large pores coated with a composite of graphite and SnSe (G-SnSe) and small pores. This simple structure provides many benefits. First, it combines two photothermal mechanisms, thermal vibration in graphite and non-radiative relaxation in SnSe, to achieve synergies in the conversion of light to heat energy. Second, compared to the single materials, graphite or SnSe alone, the nanocomposite of G-SnSe has a higher effective surface area, resulting in increased solar absorption. Finally, the melamine foam structure with bimodal pores enhances seawater wicking and has a high salt rejection capacity due to its volumetric porosity bimodal configuration of up to 35%. The monolithic melamine foam with a hierarchical photothermal structure minimizes interference with water transport due to the resistance-free presence of a continuous interfacial layer.The monolithic structure evaporaters (MSE) achieved a high evaporation rate of 1.303 kg m-2h-1 under 1 sun condition due to increased capillarity by the small-scale pores in the photothermal layer. Furthermore, spontaneous salt rejection was observed during solar desalination, attributed to the presence of intrinsic large-scale pores in melamine foam for draining the concentrated salt water from the surface. The feasibility of outdoor solar desalination was established, with a high evaporation rate of 1.259 kg m-2h-1. The mechanical stability of MSE was achieved by incorporating a small amount of binder (less than 3% of total photothermal materials), maintaining efficient performance for up to 30 days without degradation. The proposed strategy in the simple monolithic structure with bimodal porosity provides a general toolkit for designing high-performance solar desalination devices due to high evaporation rate and spontaneous salt rejection capability.In summary, the solar water evaporation technology is becoming increasingly popular as a possible replacement for traditional desalination systems. We propose a novel monolithic solar desalination system with a hierarchical photothermal structure, which is composed of a macroscale porous melamine foam as a skeleton which has both roles : an insulator and a mass transfer layer. The bimodal porous structure of melamine foam with large pores coated with a composite of graphite and SnSe provides many benefits, including increased solar absorption and a high salt rejection capacity. The MSE structure achieves a high evaporation rate and spontaneous salt rejection, making it a feasible option for outdoor solar desalination. The proposed strategy provides a general toolkit for designing high-performance solar desalination devices.

Porous freestanding FeCoMnNiSe2 medium-entropy bifunctional electrocatalyst for oxygen and hydrogen evolution reactions in alkaline medium

Efficient bifunctional electrocatalysts towards oxygen and hydrogen evolution reactions (OER/HER) in water splitting is highly desirable for fuel cells and sustainable energy storage. Herein, one novel three-dimensional medium-entropy freestanding flower-like OER/HER bifunctional FeCoMnNi diselenide (FeCoMnNiSe2) electrocatalyst is fabricated by a facile hydrothermal and selenizing method. Benefiting from three-dimensional porous frame structure, lattice distortion and synergy effects, the as-prepared FeCoMnNiSe2 presents superior OER/HER bifunctional electrocatalytic activities with the quite low overpotentials of 223.1 mV for OER and 142.2 mV for HER at 100 mA cm−2 in 1.0 M KOH. More impressively, when employed for water splitting in a full cell, this bifunctional FeCoMnNiSe2 only requires ca. 1.42 V to drive the current densities of 100 mA cm−2 and displays outstanding stability for more than 60 h in 1.0 M KOH at 10, 50, 80 and 100 mA cm−2, surpassing almost all of reported advanced non-noble metal-containing OER/HER bifunctional electrocatalysts, and showing a promising potential application for industrial-scale water splitting.

High-efficiency, thermal stable, and self-floating silver nanowires/Ti3C2Tx MXene/aramid nanofibers composite aerogel for photothermal water evaporation and antibacterial application

Interfacial solar steam generation shows great potential as a technology for seawater desalination. However, there are still considerable challenges in manufacturing photothermal evaporators with ultra-low thermal conductivity, mechanical robustness, and high-temperature resistance. Herein, we report Ag nanowires/Ti3C2Tx MXene/aramid nanofibers (Ag/Ti3C2Tx/ANFs) composite aerogel photothermal evaporators with internal three-dimensional (3D) micropores and a layered structure. The ANFs porous frame, with excellent mechanical properties and low thermal conductivity, allows abundant water transmission channels and reduces heat loss. Ti3C2Tx MXene and Ag NWs, known for their broadband absorption capability and antibacterial properties, enhance photothermal conversion efficiency. The Ag/Ti3C2Tx/ANFs composite aerogel distinguishes itself with a wide compression range (2 %∼60 %), remarkable light absorption capacity (96 %), and low thermal conductivity (0.49 W/mK), excellent thermal stability ensures the composite aerogel could withstand a wide temperature range from ∼500 °C to ∼196 °C. As expected, under one sun illumination, the Ag/Ti3C2Tx/ANFs composite aerogel presents a high evaporation rate of 2.21 kg m-2h−1 with an energy efficiency of 92 %. In addition, this evaporator composite aerogel exhibits outstanding and efficient salt tolerance, desalination, antibacterial properties, and heavy-metal ion wastewater purification capabilities. The unique evaporator structure presented here offers a new perspective for the structural design of next-generation, high-efficiency solar evaporators.

Self-floating g-C3N4/h-BN/Au photo-thermal catalysts with unprecedented thermostability at solar-activated heating condition for reusable degradation of organic pollutants

Photo-thermal catalytic (PTC) degradation as an ideal candidate for wastewater treatment is yet suffering from the unsatisfied recyclability due to the thermal effect-exacerbated serious photocorrosion of semiconductor-based catalysts. Based on polymeric graphite carbon nitride (g-C3N4) hybridized with antioxidative hexagonal boron nitride (h-BN) and grafted with stable Au nanoparticles (NPs), we provide thermostable g-C3N4/h-BN/Au nano-catalysts for high-efficient degradation of organic dyes at solar-activated heating condition. The fantastic PTC activity with optimal degradation rate up to ∼ 0.30 min−1 is far better than most mainstream hybrid catalysts. The unprecedented thermal recyclability is convincingly verified by consecutive 10 repeated tests within 500 min measurements under solar-driven heating condition (∼60 °C), wherein the negligible drop of degradation efficiency is only ∼ 0.2% lower than pristine one. The ingenious self-floating PTC membranes can be conveniently established by immobilizing the resultant nano-catalysts into bio-carbon porous frames and viscous bacterial nano-celluloses, facilitating practical wastewater decontamination in real-world scenarios.

Loofah-inspired sodium alginate/carboxymethyl cellulose sodium-based porous frame for all-weather super-viscous crude oil adsorption and wastewater treatment in harsh environment

Solar-driven viscosity reduction of highly viscous crude oil has emerged as an environmentally friendly method to address large-scale oil spills. However, the challenge lies in the limited availability of sunlight during cloudy days and at night, which hinders the effectiveness of green advanced porous materials. This study developed all-weather-available advanced porous materials in the form of loofah-like structured porous frame composed of 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane/MXene/carbon nanotubes (CNTs)/sodium alginate (SA)/carboxymethyl cellulose sodium (NaCMC). MXene and CNTs formed a continuous and stable network that enabled PMCSCPs to rapidly reduce crude oil viscosity for all-day based on photothermal and electrothermal conversions. Additionally, loofah-like porous structure and oriented pipeline biomass skeleton endowed PMCSCPs with stable and rapid adsorption capacity and speed. Considering the complexity of the external environment and oily wastewater composition, we verified the separation performance of PMCSCPs for metal ions and dyes and the ice-breaking ability under icy conditions. PMCSCPs provided a novel approach to achieving clean, high-efficiency, all-day remediation of ultra-viscous crude oil. This “Three birds with one stone” approach is expected to be obtained from nature and used on a large scale, replacing conventional porous adsorbent materials.

Bio-Template Synthesis of V2O3@Carbonized Dictyophora Composites for Advanced Aqueous Zinc-Ion Batteries

In terms of new-generation energy-storing devices, aqueous zinc-ion batteries (AZIBs) are becoming the prime candidates because of their inexpensive nature, inherent safety, environmental benignity and abundant resources. Nevertheless, due to a restrained selection of cathodes, AZIBs often perform unsatisfactorily under long-life cycling and high-rate conditions. Consequently, we propose a facile evaporation-induced self-assembly technique for preparing V2O3@carbonized dictyophora (V2O3@CD) composites, utilizing economical and easily available biomass dictyophora as carbon sources and NH4VO3 as metal sources. When assembled in AZIBs, the V2O3@CD exhibits a high initial discharge capacity of 281.9 mAh g-1 at 50 mA g-1. The discharge capacity is still up to 151.9 mAh g-1 after 1000 cycles at 1 A g-1, showing excellent long-cycle durability. The extraordinary high electrochemical effectiveness of V2O3@CD could be mainly attributed to the formation of porous carbonized dictyophora frame. The formed porous carbon skeleton can ensure efficient electron transport and prevent V2O3 from losing electrical contact due to volume changes caused by Zn2+ intercalation/deintercalation. The strategy of metal-oxide-filled carbonized biomass material may provide insights into developing high-performance AZIBs and other potential energy storage devices, with a wide application range.

Porous Single Crystals at the Macroscale: From Growth to Application.

ConspectusPorous materials have wide applications in the fields of catalysis, separation, and energy conversion and storage. Porous materials contain pores that are specifically designed to achieve expectant performance. The solid phases in porous materials are normally completely continuous to form the basic porous frame while the pores are fluid phase within the solid phase. Single crystals are macroscopic materials in three spatial dimensions with the constituent atoms, ions, molecules, or molecular assemblies arranged in an orderly repeating pattern with the ordered structures. The growth of single crystals is indeed a process to arrange these constituents in three dimensions into a repeating pattern within the materials. Today the applications of single crystals are exponentially growing in wide fields, and single crystals are therefore unacknowledged as the pillars of our modern technology. Introducing porosity into single crystals would be expected to create a new kind of porous material in which the basic porous frames are single-crystalline and free of grain boundaries. The structural symmetry is completely maintained within the basic porous frames which are a continuous solid phase, but it is completely lost inside the pores. The porous architecture is free of grain boundaries, and the fully interconnected skeletons are in single-crystalline states within the basic porous frames. Single crystals with porosities can therefore be considered to be a new kind of porous material, but they are single-crystal-like because the structural symmetry is maintained only in the skeletons and completely lost within the pores. We therefore call them porous single crystals or consider them in porous single-crystalline states to stand out with their structural features. Porous single crystals at the macroscale combine the advantages of porous materials and single crystals to incorporate both porosity and structural coherence in a porous architecture, leading to invaluable opportunities to alter the material's properties by controlling the unique structural features to enhance its performance. However, the growth of single crystals in three dimensions reduces the formation of porosities, leading to a fundamental challenge for introducing porosity into single crystals in a traditional process of crystal growth. In this Account, we report the rational design, growth methodology, and microstructural engineering of porous single crystals in a solid-solid transformation. We rationally design a high-density mother phase in a single-crystalline state and transform it into a low-density new phase in a single-crystalline state to introduce porosities into single crystals even incorporating the removal of specific compositions from the mother phase during the growth of porous single crystals. The porosity can be tailored by controlling the change in relative densities from the mother phase to the porous single crystals while the pore size can be engineered by controlling the fabrication conditions. Considering the unique structural features, we explore their functionalities and applications in photoelectrochemical energy conversion, electrochemical alkane conversion, and electrochemical energy storage. We believe that the materials, if tailored into porous single-crystalline states, would not only find a broad range of applications in other fields but also enable a new path for material innovations.