Porous Particles Research Articles

Enhancing CO oxidation performance by controlling the interconnected pore structure in porous three-way catalyst particles

Enhancing CO oxidation performance by controlling the interconnected pore structure in porous three-way catalyst particles

Characterization, adsorption kinetic and in vitro release behavior of curcumin loaded with porous mannitol and porous lactose: Template agent method vs. Pore-forming agent method.

Polyvinylpyrrolidone K30 was used as the templating agent, and ammonium bicarbonate was used as the pore-forming agent to make porous mannitol and porous lactose by the template and pore-forming agent method, respectively. Compared with the template method, the porous particles prepared by the pore-forming agent method have larger pore diameter (320.276nm and 250.528nm) and specific surface area (1.018m2/g and 0.913m2/g). The molecular docking results showed that mannitol/lactose interacted with curcumin and adhered to each other through hydrogen bonding. The adsorption kinetics process of porous mannitol and porous lactose prepared by template agent, pore-forming agent and curcumin were different. Among the curcumin-loaded porous particles prepared by the two methods, the curcumin-loaded porous lactose prepared by the pore-forming agent method had the fastest release rate and the highest cumulative release rate (95%). Curcumin releases consistent with the Peppas release kinetics model and the diffusion mechanism.

Facile synthesis of amine functionalized silica coated iron oxide nanoparticles for highly efficient removal of cefixime and ceftriaxone from wastewater

ABSTRACT A novel adsorbent, amine-functionalized porous silica-coated iron oxide nanoparticles (Fe3O4@SiO2-NH2) was prepared for the removal of cefixime (CFX) and ceftriaxone (CFT) from water. The adsorbent was then characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, transmission electron microscopy, particle size, surface area and pore size analysis. The particle size, surface area and pore size of amine functionalized silica coated iron oxide are 110 nm, 1073 m2/g and 40 Å, respectively. The effect of adsorbent dose, concentration, time duration, temperature and pH were evaluated. At optimum conditions, the removal efficiency of CFX and CFT was found to be 94.53% and 88.3%, respectively. The adsorption data of CFX and CFT onto Fe3O4@SiO2-NH2 were fully fitted with the Freundlich isotherm and followed pseudo-2nd order kinetic model. The adsorbent has strong interaction with CFX and CFT through hydrogen bonding. The adsorbent was regenerated and reused 30 times, and it was found that the removal efficiency of the adsorbent dropped only by 10%. Owing to high removal efficiency and easy preparation method, Fe3O4@SiO2-NH2 could be used as an efficient nano-adsorbent for the removal of antibiotics and other emerging contaminants from wastewater.

Rheology of dilute and semi-dilute non-Brownian suspensions made of irregular porous particles in a Newtonian fluid.

The porosity affects the rheological response of porous particle suspensions. Non-Brownian suspensions of porous particles immersed in a Newtonian Polyisobutene are investigated. Three different particles, with different porosity, pore structure and similar size, and non-porous irregular particles are used. The steady state and dynamic response of the suspensions are analyzed at several volume fractions. The behavior of the three porous particle suspensions is unique if the particle effective volume fraction, accounting for the polymer adsorbed into the particles, is considered. These suspensions are Newtonian until a critical volume fraction, beyond which they are shear thinning and exhibit a yield stress. Their rheological response differs from that of suspensions made of non-porous irregular particles as: (a) their critical volume fraction is much smaller than that of the irregular particle suspensions; (b) their viscoelastic spectra are different suggesting a denser and stronger percolated microstructure after a slow preshear. These results can be understood by considering the reduction of lubrication force induced by the porosity via two mechanisms: Darcyan flow through the porosity and propagation of the interparticle shear flow within the porosity. The first dominates at low shear rates, when the percolated microstructure is generated, the second prevails at high shear rates, where the particle clusters are disaggregated.

Comprehensive review of porous particles: Multiscale structure, flow, and transport characteristics

Comprehensive review of porous particles: Multiscale structure, flow, and transport characteristics

Increased adsorption of diflubenzuron onto polylactic acid microplastics after ultraviolet weathering can increase acute toxicity in the water flea (Daphnia magna)

The ultraviolet (UV) weathering of microplastics (MPs) can lead to higher adsorption of harmful contaminants, thus increasing the potential risks of their combined effects. Because biodegradable MPs are more susceptible to UV weathering than conventional MPs, concerns have arisen about their ecological toxicity and environmental impact. Therefore, this study investigated the mechanisms associated with the adsorption of the pesticide diflubenzuron (DFB) onto polylactic acid (PLA) MP particles after UV weathering and the acute effects (48 h) of their combination on the water flea Daphnia magna. These effects were also compared with those of the conventional MP polyethylene terephthalate (PET). UV weathering led to a greater number of cracks and pores in the PLA particles compared to PET, as well as a higher number of oxygen-based functional groups and a larger surface area. These surface changes in UV-weathered PLA particles promoted higher DFB adsorption, which in turn led to stronger acute toxicity for D. magna compared to UV-weathered PET particles. Combined exposure to 25 ng L−1 DFB and both UV-weathered and non-UV-weathered MPs significantly reduced the chitin content in D. magna, while combined exposure to 12.5 ng L−1 DFB and the MPs increased the chitin content. This effect was more pronounced for UV-weathered PLA exposure than UV-weathered PET exposure. The expression of the genes for chitinase and endocrine glycoprotein, both of which are closely associated with the toxic mechanisms of DFB, showed no significant changes with the combination of 25 ng L−1 DFB and non-UV-weathered MPs but were significantly downregulated after UV weathering. Overall, the UV weathering of PLA promoted the adsorption of DFB, thus increasing its toxic effects. Our findings demonstrate the importance of considering the effects of UV weathering and interactions with environmental pollutants when assessing the ecological risks associated with biodegradable MPs.

Tensile, Flexural, and Fatigue Responses of Lightweight Pumice-Reinforced Magnesium Composite: Experimentation Followed by an Analytical Modeling

Abstract Featherweight material to sustain mountainous loads is an extreme contrast. Still, in reality, the automobile and aerospace industries seek very light materials with high specific strength to survive in global competition. This study offers a timely answer to the problems faced by those sectors. Through the use of a stir-assisted squeeze casting method, the current investigation aims to generate a lightweight magnesium composite that is reinforced with porous low-density pumice particles at weight percentages of 5%, 10%, and 15%. An examination of the density indicates that there is a downward tendency in conjunction with the growing reinforcement. In comparison to the magnesium alloy in its natural state, the Pumice 15 coupon achieves a tensile strength increment of 47%, flexural strength increment of 35%, and a 10-time increment in service cycle at fatigue increase. The micromechanics model is implemented to justify the strengthening process in terms of the adhesion between the filler matrix and the interface shear strength. The property plots that were drafted provide evidence that the suggested material is lightweight while exhibiting a significant amount of strength in tensile, flexural, and fatigue. Post-fracture surface morphology analysis exhibits distinct tensile, flexural, and fatigue patterns.

Effect of mechanical ball milling on the microstructure and radiation shielding performance of nano-PbO

This study probes the shielding efficacy of nano-PbO, examining the effects of milling on its microstructure and the consequences on X- and gamma-ray absorption. Characterization techniques, including XRD, Raman spectroscopy, TEM, and positron annihilation spectroscopy of commercial (milled for 10, 20, and 40 h) samples, as well as the synthesized PbO, reveal that milling induces a partial phase transformation from orthorhombic to tetragonal, alters particle morphology, and increases pore volume. Notably, milling does not significantly affect X-ray attenuation. The growing particle size with lower surface area, reduction of vacancy-type defects, and expanded pore size resulting from ball milling negatively influenced the probability of interaction of gamma-rays (<250 keV). Principal component analysis highlights the interplay between particle size, surface area, defect density, and pore size in determining shielding efficacy. This investigation underscores the importance of considering multiple parameters, beyond particle size, to optimize the radiation shielding performance of any material.

A Bifunctional Iron-Nickel Oxygen Reduction/Oxygen Evolution Catalyst for High-Performance Rechargeable Zinc-Air Batteries.

Efficient and robust electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucial for fuel cells, metal-air batteries, and other energy technologies. Here, a highly stable, efficient bifunctional OER/ORR electrocatalyst (FeNi-NC@MWCNTs) is reported and demonstrated its integration and robust performance in an aqueous Zinc-air battery (ZAB). The catalyst is based on neighboring iron/nickel sites (FeNiN6) which are atomically dispersed on porous nitrogen-doped carbon particles. The particles are wrapped in electrically conductive multi-walled carbon nanotubes for enhanced electrical conductivity. Electrocatalytic analyses show high OER and ORR performance (OER/ORR voltage difference = 0.69V). Catalyst integration in a ZAB results in excellent performance metrics, including an open circuit voltage of 1.44V, a specific capacity of 782 mAh g-1 (at j = 15mA cm-2), a peak power density of 218mW cm-2 (at j = 260mA cm-2) and long-term durability over 600 charge/discharge cycles. Combined experimental and theoretical (density functional theory) analyses provide an in-depth understanding of the physical and electronic structure of the catalyst and the role of the FeNi dual atom reaction site. The study therefore provides critical insights into the structure and reactivity of high-performance bifunctional OER/ORR catalysts based on atomically dispersed non-critical metals.

Poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) Monolith with Dual Porosity for Size Exclusion Chromatography.

The use of polymeric monoliths as stationary phases for liquid chromatography has been limited, despite their ability to enhance the convection flow of the mobile phase with respect to particulate-based columns. This is due to a poor balance between the volume of flow through pores and the number of active sites within polymeric monoliths. In this paper, we present the obtainment of poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) (P(GMA-co-EDMA)) monoliths with dual pore size distributions (with pore sizes of 60 and 550 nm). Hierarchical pore size distributions were achieved by performing the monolith synthesis by reversible addition-fragmentation chain transfer (RAFT) polymerization as well as using ternary porogen mixtures (containing PEG, dodecanol, and dioxane). While the controlled polymerization mechanism promoted mesopores in the monolith, ternary porogen mixtures allowed the formation of macropores. The monoliths obtained were used as stationary phases for size exclusion chromatography (SEC) for the separation of poly(methyl methacrylate) standards with molar masses between 2.50 × 103 and 3.06 × 106 g/mol, allowing selectivities that were comparable with commercially available SEC columns packed with porous particles. We believe the approach presented in this work could be the first step toward the obtainment of stationary phases for SEC with enhanced accessibility of exclusion pores. Monolithic columns with accessible porous structures can be beneficial for size-based separations of ultrahigh molar mass analytes with low diffusion coefficients.

Effects of precoating color formulation with coarse ground calcium carbonate and porous precipitated calcium carbonate on paperboard properties and printability

To identify suitable pigments for the precoating of paperboard, the rheological properties of coating colors and their effects on the surface and printing properties of coated paperboard were evaluated with respect to the type and combination of coating pigments. The investigation included porous precipitated calcium carbonate (PCC) and four types of coarse ground calcium carbonate (GCC) of different sizes. As the GCC particle size increased, the viscosity of the coating color decreased in the low-shear region, and the degree of dehydration increased. Coatings containing PCC, which comprised relatively small and highly porous particles, were found to be less dehydrated than coatings containing only GCC. The surface roughness of the coated paperboard increased as the GCC particle size increased, leading to reduced paper gloss. However, increasing the GCC particle size decreased the binder usage and increased surface strength. In conclusion, it is believed that the use of 55-grade GCC rather than the smaller size of 60-grade GCC can reduce costs and enhance surface strength by reducing binder and energy.

(Invited) Characterization of Atomic- and Nano-Scale Defects in Ni-Rich Layered Cathode Materials through Neutron and X-Ray Scattering Techniques

Ni-rich layered cathode materials have garnered significant attention as promising candidates for Li-ion batteries due to their high energy density. Although extensive research efforts focus on enhancing the structural stability of these materials through elemental doping, surface coating, and the use of electrolyte additives, the intrinsic chemical-mechanical instability caused by atomic- and nano-scale defects during the synthesis process remains a substantial challenge.Recent studies have focused on improving the cycle life of Ni-rich layered cathodes by fundamentally enhancing Li/O insertion. These enhancements have been achieved by regulating key parameters, including excess-Li content, temperature, and oxygen atmosphere during synthesis, often without the need for additional treatments. Additionally, a pre-calcination stage at 200–500°C is typically employed during synthesis to efficiently decompose the precursor. However, the precise rationale behind Li overloading remains largely unexplored, and comprehensive studies on the impact of the pre-aging process on the crystal structure and morphologies of Ni-rich NCM materials are notably scarce.In this study, we investigate the atomic- and nano-scale structural evolution of the Ni-rich layered cathode using X-ray/neutron scattering and electron/X-ray microscopy. Our findings reveal that excessive Li can be integrated into the transition metal layer of the layered structure by modulating the Li content and synthesis temperature. We present the first quantification of nanoscale pores in primary and secondary particles of the Ni-rich cathode using small-angle X-ray and neutron scattering analyses. Furthermore, we propose a simplified synthesis route aimed at mitigating the formation of multi-scale defects in Ni-rich layered cathodes, leading to superior electrochemical cycle stability. This research provides crucial insights into defect characterization and management, potentially driving advancements in the design and production of high-performance Ni-rich layered materials.

(Invited) Neutral Seawater Splitting of Perovskite Oxynitrides Under Sunlight via Alternative Oxidation Reactions

Photo-electrochemical (PEC) seawater splitting using semiconductors is a promising means of directly producing hydrogen from seawater occupying approximately 97% of Earth’s water. The n-type perovskite oxynitride semiconductors with a general formula AB(O,N)3 (A=Ca, Sr, Ba or La; B=Ti, Nb or Ta) are capable of absorbing intensive visible light up to 750 nm wavelength, thermodynamically leading to high solar-to-hydrogen conversion efficiency of 10% or above.1 Also, their band positions straddle various oxidation and reduction potentials including the water redox potential to produce value-added energy resources such as H2, HCOOH, and NH3.2 Based on the favorable optical properties, the water splitting activity using the oxynitrides has been significantly increased in strong alkaline electrolytes, although it is still low in neutral electrolytes.2-3 Oxygen evolution reaction (OER) is driven via four-electron oxidation. Its kinetics is commonly very sluggish in neutral aqueous solutions, which the significant overpotential is required to catalyze it. Thus, applying alternative oxidations to OER, such as chlorine evolution reaction (CER), may be a feasible approach to efficient hydrogen production in neutral seawater electrolytes.4 In terms of thermodynamic potential, OER (E 0 = 1.23 VNHE) is more oxidative than CER (E 0 = 1.36 VNHE). However, CER driven via two-electron oxidation can be catalyzed faster than OER kinetically in neutral electrolytes.Herein we first present sunlight-driven seawater splitting activity of perovskite AB(O,N)3 largely improved in neutral environments and also discuss CER activity depending on various pH values as an alternative oxidation to OER. Highly-crystalline, porous SrNbO2N particles grown on Nb substrate was prepared by bottom-up fabrication including oxidation of Nb substrate and flux-assisted nitridation.5 The advanced fabrication caused less-defective oxynitride with a large surface area. The resulting SrNbO2N/Nb photoanode produced significant OER photocurrent in 0.2 M NaPi electrolyte at a neutral pH 6.4, and the photocurrent was three times increased by adding 0.5 M NaCl to catalyze CER simultaneously. Moreover, the onset potential for seawater splitting including CER was shifted to a lower potential by approximately 0.1 VRHE than that for water splitting leading to OER exclusively. These results clearly demonstrate that CER was preferentially catalyzed during neutral seawater splitting compared with competitive OER. It also implies that CER kinetics over the SrNbO2N was faster than OER kinetics despite its unfavorable thermodynamic potential.The BaTaO2N/Ta photoanode, more photoactive and stable than the Nb-based oxynitrides, was synthesized in the similar manner. The seawater splitting of the oxynitride at different pH values was further investigated, and the quantitative analysis of the resulting products, namely, H2, O2, and ClO− was also performed to determine the operating conditions suitable for efficient and stable seawater splitting. Moreover, different electro-catalysts to improve the selectivity to CER were evaluated in the artificial seawater. The enhanced seawater splitting activity and selectivity to CER of the AB(O,N)3 in artificial seawater will be discussed in detail in a presentation. References J. Seo, H. Nishiyama, T. Yamada, K. Domen, Angew. Chem. Int. Ed., 2018, 57, 2.J. Seo, K. Domen, Mater. Chem. Front., 2024, 8, 1451.J. Seo, T. Hisatomi, M. Nakabayashi, N. Shibata, T. Minegishi, M. Katayama, K. Domen, Adv. Energy Mater., 2018, 1800094.C.R. Lhermitte, K. Sivula, ACS Catal., 2019, 9, 2007V-H. Trinh, J. Seo, ACS Sustain. Chem. Eng., 2023, 11, 1655

Approaches to Improve Both Cycle and Calendar Life of Silicon-Based Lithium-Ion Batteries

During the last few decades, silicon (Si) has been extensively investigated as the next generation of anode material for lithium (Li)-ion batteries (LIBs) due to its high theoretical capacity (~ 4200 mAh g−1) which is more than ten times larger than those of graphite anode materials. However, because of the huge volume changes (~ 300%) of Si during repeated lithiation and delithiation, its lower electrical conductivity, inconsistent kinetics reaction, and relatively low initial Coulombic efficiency (ICE), large-scale application of Si-based LIBs (Si-LIBs) is still limited. The abovementioned intrinsic characteristics of Si trigger the short cycle life of Si-LIBs due to several reasons: 1) pulverization of Si particles; 2) Increasing cell impedance associated with continuous growth of solid electrolyte interphases (SEI) layers, 3) Poor structural integrity of the electrodes. In addition, the calendar life of Si-LIBs is still less than two years, which is far less than the ten-year calendar life required for electric vehicle applications. To improve both cycle life and calendar life, we have developed a low-cost, pitch-based carbon coating approach to synthesize micron-sized porous Si particles. A novel etching method is also developed to prevent overheating and bubbling during the Si etching process. Recently, we have developed a novel electrolyte based on the concept of localized high concentration electrolyte tailored for Si-LIBs. It leads to the formation of stable interphase layers on both the anode and cathode and effectively blocks the crosstalk between the electrodes, minimizing the impedance increase of Si||LiNi0.6Mn0.2Co0.2 (NMC622) batteries during storage at elevated temperature (55°C), therefore largely improves their calendar life. Si||NMC622 batteries using this electrolyte also demonstrated high-capacity retention of 92.4% after 500 cycles at 45°C with well-preserved electrode structures. More details on the development of Si-LIBs in PNNL will be presented in this talk.

(Invited) Development of Biosensors Based on Graphene-Coated Porous Silica Spheres

During the onset of the COVID-19 pandemic, the public was reminded of how quickly routine diagnostic tests could overwhelm the health-care system when no other options are available. As mass adoption of the at-home rapid tests were developed and accepted thereby relieving the first responders to care for more critically ill patients, it sparked a resurgence of interest in affordable point-of-care (POC) diagnostics. Currently, besides a handful of common POC devices (e.g., glucose sensor, pregnancy tests and COVID test) there are not many commercially successful examples due to complex design, high production costs, and material stability for field deployment. In this study, we demonstrate that graphene coated porous silica spheres (G/PSS) can be a simple and affordable material for target sensing. Porous carbons particles are low-cost materials widely used as electrode materials in applications such as electric double layer capacitors, batteries, biofuel cells, and biosensors. In the above applications, the non-uniformity of the particles does not interfere with their performance. However, for target sensing, the reduction of noise is generally achieved by working with uniform material. In our case, we developed a method to synthesize uniformly coated graphene on uniformly sized porous silica. The triple pore structure and increased surface area enable, the diffusion of enzymes, mediators, and substrates for rapid enzyme electrode reactions - the mesopores provide a reaction field, the micropores trapping mediators, and the macropores providing substrate, mediator, and enzyme diffusion. Of particular interests to the audience are three key areas: 1) the development of porous silica spheres with controllable particle size and pore size, 2) the graphene chemistry to deposit graphene on to the particles as developed and 3) fine-tuned by our group for this application, and the fabrication technical to prepare electrodes using screen-printing. We succeeded in developing a sensor chip with G/PSS arranged on the surface with high efficiency by selecting a mediator that can smoothly transfer electrons to and from the carbon, which enables various sensing applications. Furthermore, to expand the portfolio of new and improved components that increase the field usability of POC diagnostic devices, we demonstrate that Prussian blue (PB) dispersed in G/PSS functions as an effective and affordable reference electrode as a promising alternative to industry standards. The solubility product of PB is approximately only 1/1031 of that of AgCl, rendering PB a water-insoluble electrode that is free from metal leaching in small devices. The support material, G/PSS, provides conductive mesopores that accommodate insulating PB clusters, ensuring effective contact between the PB clusters and electrolytes and stable potential. Furthermore, the monodisperse spherical shape of G/PSS is beneficial for the production of a reference electrode for POC devices through a low-cost, highly reproducible screen-printing process. This study successfully demonstrated the feasibility and stability of the prototype small biosensor, opening the door for future improvements in the device’s ability to perform similar sensing in complex media such as biological samples.

Tailored 3D Porous N-Doped Carbon Nanospheres for Bottom-up Electrode Design - Independent Pore and Particle Size Control for the Use in Model Electrodes

Design of porous carbon-based electrode materials and derived porous electrode structures is crucial for the performance of electrochemical energy storage and conversion devices. In that context carbon-based electrode material building blocks with well-defined properties are desired. Such properties include controlled morphology (preferably spherical), particle size, and intra-particle porosity along with controlled composition, surface chemistry, and processability. These factors influence the particle arrangement and electrode structure during processing, as well as electrolyte interaction, distribution, and mass transport phenomena within the electrode.In this work, we introduce a hard-templating method for producing highly uniform meso- and macroporous N-doped carbon nanospheres with independently tuneable pore and particle sizes, serving as a versatile material platform for the bottom-up design of 3D porous carbon electrodes. We could thereby customize the pore sizes between approximately 10 to 100 nm at a constant particle size, while particle sizes between 50 and 300 nm could be achieved for a constant pore size. Other physicochemical parameters such as chemical composition, graphitization, and surface functionalization remained constant across all samples, allowing for the exclusive investigation of pore and particle size effects independently from each other.We further used our different N-doped carbon nanospheres as building blocks for 3D porous electrodes and studied these in electrochemical double-layer capacitors with the aim to (i) showcase the versatility of our materials and (ii) examine pore and particle size effects on the performance. Indeed, electrochemical double-layer capacitors serve as an excellent model system for such investigations due to their sensitivity to carbon particle surface area, pore size, and mass transport phenomena within the 3D percolated structure of porous carbon electrodes.

Mechanistic Modeling of Pollutant Mass Redistribution (Sorption/Desorption) in Heterogeneous Systems Explaining Unexpected Slow Kinetics.

Redistribution of pollutants between different solid phases occurs frequently in field and laboratory settings. Examples include the input of urban particles carrying pollutants into soils or rivers with suspended particles or passive sampling. Since multiple mass transfer mechanisms are involved and natural particles typically are very heterogeneous, modeling of sorption/desorption kinetics is challenging. Here, we present a semi-analytical model formulated in the Laplace domain to simulate pollutant redistribution kinetics in heterogeneous systems. The model accounts for a coupled process governed by intraparticle and external boundary layer diffusion, and it considers the heterogeneity of various sorbents (e.g., geometric shape, size, sorption capacity coefficient, and solid and porous particles). The model is validated against data of two batch experiments: (i) the redistribution of phenanthrene in spherical polyethylene particles of different sizes and (ii) redistribution of anthracene-d10 and phenanthrene in a heterogeneous sediment suspension with polyethylene passive samplers. It allows to explain the temporary overshooting of concentrations in the aqueous phase due to different kinetic controls of various particles involved (fast desorption vs. slow sorption) as well as initial fast kinetics followed by surprising long tailing in batch experiments. The approach is very flexible and can be used for many different scenarios.

Titanium Oxysulfate‐Derived 1D Lepidocrocite Titanate Nanostructures

AbstractNanostructured titania, TiO2, holds significant importance in various scientific fields and technologies for their distinctive properties and multipurpose characteristics. In this article, the facile, economical, and scalable synthesis of 1D lepidocrocite, 1DL, titania nanostructures derived from a water‐soluble Ti precursor, titanium oxysulfate (with oxidation of Ti+4) at temperature &lt;100 °C under atmospheric pressure is discussed. Titanium oxysulfate with tetramethyl ammonium hydroxide, TMAH, is simply reacted to yield individual lepidocrocite titania‐based chain‐forming nanofilaments, NFs, 6 × 6 Å2 in minimal cross‐section and aspect ratios of ≈20 1DLs. If only ethanol is used for washing, the 1DL self‐assemble into ≈10 µm, porous mesostructured particles, PMPs. If water is used, quasi‐2D sheets form instead. Characterization of the resulting powders showed them to be quite similar to those derived from TiB2, and other water‐insoluble Ti precursors. The 1DL bandgap energies are ≈4 eV, due to quantum confinement. They adsorbed rhodamine 6G. The latter also sensitized the 1DLs and allowed for dye degradation using only visible light. Used as electrodes in supercapacitors, the 1DLs can be cycled over 1.6 V and result in high power densities (300 W kg−1). Stronger birefringence started to appear in samples with concentrations &gt;15 gL−1 indicating the formation of a liquid crystal phase. This new synthesis protocol enables the cheaper scalable production of 1DLs with significant implications across various fields.

Size-Dependent Effects of ZIF-8 Derived Cathode Materials on Performance of Zinc-Ion Capacitors.

Zinc-ion capacitors (ZICs) have attracted great attention due to a series of advantages. However, the cathode materials are still the bottleneck for high-performance ZICs to be achieved. Therefore, ZIF-8-derived porous carbons are one of the most promising candidates but ZIF-8 nanoparticles with different sizes exhibited various electrochemical performances in ZICs. Herein, a series of monodispersed ZIF-8 nanoparticles are first prepared by a temperature-controlled process to fabricate the corresponding ZIF-8-based porous carbon nanoparticles with pre-designed sizes. The as-prepared materials have been tested as cathode materials in ZICs. Thus, their size effect allowed us to disclose its correlation with other factors such as ion transport/storage and capacitance. The results reveal that the optimal-sized porous carbon particles can effectively shorten the ion transport distance and accelerate the ion diffusion rate, resulting in lower electrical resistance, larger ion diffusion coefficients, and faster electron transport. The presented findings can facilitate the design of new advanced cathode materials paving the way for the development of high-performance cathode materials for ZICs in the future.

Microfluidic Precision Manufacture of High Performance Liquid Chromatographic Microspheres

AbstractA key bottleneck in developing chromatographic material is the chemically entangled control of morphology, pore structure, and material chemistry, which holds back precision material manufacture in order to pursue advanced separation performance. In this work, a precision manufacture strategy based on droplet microfluidics was developed, for production of highly efficient chromatographic microspheres with independent control over particle morphology, pore structure and material chemistry. The droplet‐synthesized microspheres display extremely narrow particle size distribution (CV&lt;3 %), enabling a 100 % production yield due to complete elimination of sieving steps. More importantly, the size of the droplet‐synthesized microspheres is freely adjustable without the need for re‐optimizing chemical recipes or reaction conditions. The resulting materials exhibit excellent separation efficiencies, achieving a reduced plate height of hmin=1.67. This precision manufacture strategy also allows for flexible pore design and continuous pore size adjustment across three orders of magnitudes, providing a novel vehicle for resolution fine‐tuning targeting protein separation. Besides traditional silica, organic–inorganic hybrid silica, zirconia, and titania microspheres can also be precisely synthesized on the same platform, supporting various separation applications and operating conditions. Powered by precision manufacture, super‐throughput production, and versatile chemistry, the high‐performance droplet‐synthesized separation material will pave the way towards green and precision chromatographic industry.