Changes In Crystal Morphology Research Articles

Effects of interesterification with solid base catalyst on physicochemical properties of lard and high-oleic sunflower oil blends

Interesterified blends of lard (LA) and high-oleic sunflower oil (HOSO) were prepared by using a self-synthesized solid base catalyst (K2CO3/GCN). The effect of interesterification on the physicochemical properties of blends was investigated by analyzing the triacylglycerol (TAG) composition, slip melting point (SMP), solid fat content (SFC), thermal properties, crystal polymorphism, and micromorphology. The results proved that interesterification significantly modified the physicochemical properties of the blends. The interesterified products had lower SMPs and steeper SFC curves than the individuals. The interesterified product (CIE-5:5) had the widest plastic range (5.7-18.6°C), and its increase rate of OPO and OPL total content was up to 38%. The differential scanning calorimetry melting and cooling thermograms showed an obvious change after interesterification. These changes were mostly due to the alternations in TAG compositions. The wide-angle X-ray diffraction results indicated that the crystal form of blends transformed from β′ to β-form after interesterification. Because of the transformation of crystal polymorphism, the micromorphology of interesterified blends differed greatly from the physical blends at the same ratio. The changes in crystal morphology are beneficial for the application of LA-HOSO blends. This work provides an alternative option for extending the use of native lard and high-oleic sunflower oil.

Effect of crystallization behavior on wear properties of polytetrafluoroethylene composites modified by irradiation above melting point

AbstractIn this paper, the reasons for the improved wear resistance of irradiation‐modified Polytetrafluoroethylene (RM‐PTFE) and its composites above the melting point were investigated from the microcrystalline point of view by using methods such as crystallization kinetics, and it was found that the linear wear rate of RM‐PTFE was only 0.3 um/km, with a 1000 times increase in wear resistance, which was due to the transformation of its crystals from flake crystals that were easily dislodged to spherical crystals that were more resistant to abrasion. It was also found that the linear wear rate of Polytetrafluoroethylene (PTFE) with coke and graphite was 0.2 and 0.1 μm/km, respectively, and the abrasion resistance was further improved, which was attributed to the lowering of spherical crystal grain size by coke and graphite, which had better mechanical properties. These studies lay the foundation for future research on the frictional wear mechanism of RM‐PTFE above the melting point.Highlights Irradiation‐modified PTFE above the melting point Wear resistance of PTFE increases 1000 times Changes in crystal morphology dramatically increase wear resistance Use of crystallization kinetics to study the crystalline form of PTFE Small grain size improves wear resistance

Synthesis and electrochemical properties of microcanals Mg-S-Cu-S as an electrode material for energy storage applications

The synthesis of novel nanostructured electrode materials is the community demand to overcome energy crises. Herein, the nanostructured copper-sulfide, copper-cadmium-sulfide and copper-magnesium-sulfide (Cu-S, Cd-S-Cu-S and Mg-S-Cu-S) electrodes are synthesized by chemical vapor deposition technique. The changes in crystal growth and surface morphologies of Cu-S, Cd-S-Cu-S and Mg-S-Cu-S electrodes are associated with the formation of heterostructures and change in energy fluxes. The weight % of Ni, Cu, S; Ni, Cd, Cu, S; and Ni, Mg, Cu, S are found to be 8, 62, 30; 6, 16, 48, 30; 15, 14, 45, 26 are observed in Cu-S, Cd-S-Cu-S and Mg-S-Cu-S electrodes respectively. The Mg-S-Cu-S electrode showed superior specific capacitance of 4393 and 5657 F/g at 1 mV/s and 1.0 A/g respectively. The maximum energy density and power density of Mg-S-Cu-S electrode are found to be 141 Wh/kg and 2120 W/kg respectively. The cyclic retention after 3000 cycles of Cu-S, Cd-S-Cu-S and Mg-S-Cu-S electrodes are found to be 80.8, 87.5 and 96.2 % respectively. The simulation results show that the Cd-S-Cu-S followed more capacitive-controlled while Mg-S-Cu-S followed more diffusive controlled process. Result show that the Mg-S-Cu-S electrode is comparatively more suitable for portable energy storage devices.

Influence of Different Ions on Pulse Electrodeposition of CaCO3 Scales in the Simulated Seawater.

In the circulating water system of coastal power plants, various kinds of ions have a great influence on the formation and growth of CaCO3 scales. This paper focuses on investigating the influence of existing ions on the pulse electrodeposition behaviors of CaCO3 scales. Different concentrations of ions, such as Fe3+, Mg2+, PO43- and SiO32-, are introduced to simulate the actual seawater environment, and their influence on the CaCO3 scale deposition behaviors is assessed by linear sweep voltammetry, chronoamperometry, and electrochemical impedance spectroscopy tests. The surface coverage of the CaCO3 scale layer is evaluated through the residual current density and polarization resistance values, while the crystal structure and surface compactness of the layer are confirmed by the scanning electron microscope and X-ray diffractometer tests. Results indicate that high concentrations of Mg2+, Fe3+, and PO43- ions have the most significant inhibitory effect on the pulse electrodeposition of CaCO3 scales, among which the inhibition effect of Mg2+ ions is mainly reflected in the change of crystal morphology of CaCO3, that is, the crystallization growth process is inhibited. The inhibition effect of PO43- ions is mainly reflected in the gradually reduced coverage and density of CaCO3 crystals on the electrode surface, suggesting that the crystallization nucleation process is inhibited, while Fe3+ ions have a certain inhibition effect on both the crystallization nucleation and growth processes. Furthermore, lower concentrations of SiO32- ions also display a significant inhibition effect on the crystallization nucleation and growth process, and the inhibition effect weakens with increased concentration. This study provides a theoretical basis for exploring the removal of ions in the industrial water softening field.

Laser‐Induced Nucleation of Acetaminophen through the Addition of Insoluble Impurities and Acidic Polymers

AbstractThis study investigates the crystallization of acetaminophen (ACET) in ultrapure water and a 10 wt.% aqueous polyacrylic acid (PAA) solution using non‐photochemical laser‐induced nucleation (NPLIN) for the first time. Using a 532 nm nanosecond laser, two distinct crystal morphologies—rhombic and tetragonal plate‐like—are formed in both solvents after adding impurities. Notably, the PAA solution showed a reduced number of crystals and slower growth rates compared to ultrapure water, suggesting that the acidic polymer modulates crystal growth. Interestingly, crystals are not induced by the laser without impurities. However, impurities like copper phthalocyanine (CuPc) or boron carbide (CB4) enabled successful NPLIN, with CB4 showing higher nucleation efficiency than CuPc. The study also explores how laser power affects nucleation probability and identifies potential laser energy thresholds. Experimental data on ACET crystal sizes over time are fitted to derived equations, which accurately represented trends and predicted results. The nanoparticle heating mechanism and the role of acidic polymers in affecting nucleation probability and growth rate are discussed, along with potential mechanisms for changes in crystal morphology.

III-Nitride Magnetron Sputter Epitaxy on Si: Controlling Morphology, Crystal Quality, and Polarity Using Al Seed Layers.

Group III-nitride semiconductors have been subject of intensive research, resulting in the maturing of the material system and adoption of III-nitrides in modern optoelectronics and power electronic devices. Defined film polarity is an important aspect of III-nitride epitaxy as the polarity affects the design of electronic devices. Magnetron sputtering is a novel approach for cost-effective epitaxy of III-nitrides nearing the technological maturity needed for device production; therefore, control of film polarity is an important technological milestone. In this study, we show the impact of Al seeding on the AlN/Si interface and resulting changes in crystal quality, film morphology, and polarity of GaN/AlN stacks grown by magnetron sputter epitaxy. X-ray diffraction measurements demonstrate the improvement of the crystal quality of the AlN and subsequently the GaN film by the Al seeding. Nanoscale structural and chemical investigations using scanning transmission electron microscopy reveal the inversion of the AlN film polarity. It is proposed that N-polar growth induced by Al seeding is related to the formation of a polycrystalline oxygen-rich AlN interlayer partially capped by an atomically thin Si-rich layer at the AlN/Si interface. Complementary aqueous KOH etch studies of GaN/AlN stacks demonstrate that purely metal-polar and N-polar layers can be grown on a macroscopic scale by controlling the amount of Al seeding.

Changes in crystal morphology induced by lanthanide doping into diacetylene lamellar crystals

In this study, we show that doping lanthanides into lamellar crystals reorganizes the lamellar structure and dramatically changes the crystal morphology. Azo-DA, a compound with azobenzene derivatives and carboxylic acids at both ends of the diacetylene moiety, formed plate-like lamellar crystals. The doping of holmium (Ho), a lanthanide, into the film obtained by stacking Azo-DA lamellar crystals, promoted a dramatic change in crystal morphology, resulting in the formation of an Azo-DA/Ho film with a radial lamellar crystal structure. A detailed investigation of the crystal growth process revealed that Azo-DA/Ho, which is slightly formed in the solution phase during Ho doping, acts as a pseudonucleating agent and dramatically changes the morphology of the lamellar crystals. Additionally, the morphological changes in the lamellar crystal films significantly changed the surface properties of the films, such as their appearance and water repellency. Similar morphological changes in lamellar crystals were induced when other lanthanide elements were used instead of Ho, and the type of lanthanide dopant can affect the magnetic properties of the films.

The Crystallization Morphology and Conformational Changes of Polypropylene Random Copolymer Induced by a Novel β-Nucleating Agent.

The crystal morphology and conformational changes during crystallization of a polypropylene random copolymer (PPR) are the basis for understanding its crystallization process. In this work, novel rare-earth β-nucleating agent WBN-28 was directly added into PPR to induce β-crystallization. The results of differential scanning calorimetry (DSC) showed that it has an excellent β-crystal-induced effect. The β-crystal content could surpass 85%, calculated from wide-angle X-ray diffraction (WAXD) data. The morphology of the β-crystal and α-crystal was intuitively observed via a polarizing optical microscope (POM). The β-crystallites were interconnected to naturally develop plate-like crystalline regions possessing a certain size, and the α-crystallites with sufficient thicknesses possessed a cross-hatched phenomenon. The bundle-like supramolecular structure of the β-crystal induced by WBN-28 was further observed via a scanning electron microscope (SEM). The conformational changes in the crystallization process of PPR were resolved via high-resolution infrared spectroscopy to understand its β-crystallization in depth. The conformational changes during the crystallization of PPR were found to be different from those of the isotactic polypropylene homopolymer (PPH); they had their own characteristics. This will provide guidance for understanding the β-crystallization of PPR in depth.

Synthesis of terpolymer from Helianthus annuus (natural oil) and evaluation as pour point depressant and viscosity reducer on Indian crude oil

Pour Point Depressant is introduced to crude oil at ppm level to overcome transportation problem of crude oil because of its complex chemical structure. Synthesized PPDs improve flow property, viscosity and also improve its numerous parameters to improve performance of crude oil. Low molecular weight and high molecular weight, copolymer having better PPD types. In present work, synthesized Terpolymer, from natural source, was formed from the reaction with Helianthus annuus oil and ester of Erucic Acid with various fatty alcohol. It was evaluated for its properties on Indian waxy crude oils, i.e., From Limbodra well. Structure and molecular weight of synthesized polymer was confirmed by Spectral data and Gel permeation chromatography (GPC). Also its effect on crude oil was evaluated by Rheological studies, SARA Analysis, Pour point depressant effect. Cross–polarizing microscopic studies were performed to study changes in morphology of wax crystals in crude oil with and without additive. A zero friction advanced Rheometer AR-500 was used to determine the viscosity by applying Bingham plastic-flow model.

An investigation into proton conduction of ga doped boehmite based memristor with simulated synaptic behavior

Artificial synapses based on protonic memristor have great potential in constructing neural morphological computing system. However, further investigation is still required to understand the proton conduction mechanism of protonic memristors. Here, we present a new type of Ga doped boehmite based memristors with artificial synapse functionality, which can achieve variations in conductance levels by precise control of the Ga doping content. Compared with undoped boehmite, there is no obvious change in crystal structure, particle morphology and chemical bond doped with different of concentration Ga. The change in the electrical conductance is found to be a result of proton transfer, closely resembling what takes place in biological neurons. Furthermore, the first-principle density functional theory (DFT) calculation is conducted to elucidate the proton conduction mechanism and zig-zag-like pathways for proton transfer in the memristor was proposed. The results establish a precedent for tuning the proton transfer behaviour in memristor-based neural devices, thereby enhancing their practicality. It provides a novel approach for studying the resistance switching behavior in proton transfer-based memristors.

Performance of ionic liquid functionalized metal organic frameworks in the adsorption process of phenol derivatives.

The growth of industrial activities has produced a significant increase in the release of toxic organic pollutants (OPs) to the environment from industrial wastewater. On this premise, this study reports the use of metal organic frameworks (MOFs) impregnated with various ionic liquids (ILs) in the adsorption of phenol derivatives, i.e., 2,6-dimethylphenol and 4,4'-dihydroxybiphenyl. MOFs were prepared starting from 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) with divalent (Co, Ni, Cu) and trivalent (Ce) metal salts in mild hydrothermal conditions using water as a green solvent. Imidazolium base ionic liquids, namely 1-butyl-3-methylimidazolium trifluoromethanesulfonate, 1-butyl-3-methylimidazolium nitrate, 1-butyl-3-methylimidazolium chloride, and 1-hexyl-3-methyl-imidazolium chloride, were used to modify MOFs, leading to composite materials (IL@MOF), which show the structural characteristics of MOFs, and complement the advantages of ILs. SEM, EDX images, and TG data indicate that the IL is just attached on the surface of the adsorbent material, with no changes in crystal size or morphology, but with slightly altered thermal stabilities of IL@MOF composites compared to the original ILs and MOFs, pointing to some interionic interaction between IL and MOF. This research consists of equilibrium experiments, studying the effect of the initial concentration of OPs on the adsorption efficiency of the as-prepared MOFs and IL@MOF, in order to determine the influence of the nature of the adsorbent on its developed adsorption capacity and to investigate the performance of both ILs and MOFs. To determine the maximum adsorption capacity, several empirical isotherms were used: Langmuir, Freundlich, Redlich-Peterson, and Dubinin-Radushkevich. The characteristic parameters for each isotherm and the correlation coefficient (R2) were identified. The IL modification of MOFs increased the adsorption capacity of IL@MOF for the removal of phenol derivatives from aqueous solution. The adsorption capacity function of the MOF structure follows the trend CeHEDP > CoHEDP > NiHEDP > CuHEDP. The best performance was achieved by adsorbent materials based on Ce.

Comparative analysis of thermal stability and electrochemical performance of NaNi1/3Fe1/3Mn1/3O2 cathode in different electrolytes for sodium ion batteries

The electrochemical compatibility and thermal stability of cathode and electrolyte guarantee the intrinsic safety of batteries. The NaNi1/3Fe1/3Mn1/3O2 (NaNFM) cathode for sodium ion batteries (SIBs) has not received, sufficient attention concerning its thermal safety compared to its electrochemical properties. Herein, we investigated the thermal stability of NaNFM, exothermic reaction and electrochemical performance of NaNFM with various electrolytes. The comprehensive electrochemical performance of NaNFM in different electrolytes followed this sequence: sodium hexafluorophosphate (NaPF6) > sodium bis(trifluoromethyl-sulfonyl)imide (NaTFSI) > sodium perchlorate (NaClO4)- based electrolytes. Additionally, ethylene carbonate (EC): propylene carbonate (PC)- type electrolytes displayed superior cycling stability compared to ethylene carbonate (EC): diethyl carbonate (DEC)- type electrolytes. Moreover, the heat flow profiles demonstrated that the thermal stability between NaNFM and various electrolytes could be ordered according to the total heat release as: NaClO4 < NaPF6 < NaTFSI-based electrolyte. X-ray diffractometer (XRD), scanning electron microscope (SEM) and x-ray photoelectron spectrometer (XPS) analyses were carried out to investigate the changes in crystal structure, morphology and valence state of thermal reaction products after microcalorimetric analysis experiments. These findings provide valuable insights for the safe application of the NaNFM cathode in SIBs.

Understanding and Comparing the Stability of Water- Versus NMP-Based Tin(IV)Sulfide Electrodes Using Post-Mortem Analysis

The market for lithium-ion batteries (LIBs) has experienced a tremendous growth since 1991, when the first LIB was commercialised by Sony, and it is expected to grow even further. The reason for this upward trend is on the one hand the improvement in performance, specifically in energy density and cyclability, and on the other hand the world’s increase in energy demand. LIBs are now able to power not only small electronic devices but also electric vehicles and stationary energy storage systems.In addition to the increased need for batteries with high energy densities, environmental aspects must also be considered. Firstly, commercial LIBs contain critical raw materials (CRM) such as Li, Co, and graphite which are often concentrated in a few areas of the world and are sometimes mined using techniques which exploit both humans and the planet. Secondly, the use of toxic chemicals such as N-methyl-2-pyrollidone (NMP) in electrode manufacturing raises concerns on the degree of sustainability of the product. Furthermore, in order to reduce the CO2 emissions and achieve climate-neutrality by 2050, the EU (BATT4EU) has set goals regarding energy densities, battery life time and safety. Desired values for gravimetric and volumetric energy densities for Generation 3 LIBs are considered 350-400 Wh/kg and 750-1000 Wh/l respectively for 2000+ cycles. These energy values can be achieved by either developing cathodes with higher voltage and/or by developing cathodes and anodes with higher specific capacity. The latter approach together with sustainability aspects are addressed in this work. Tin(IV)sulfide (SnS2) has been investigated in the last few years as one of the most promising anode materials for Li-ion batteries due to its high theoretical specific capacity of 1209 mAhg-1 compared to commonly used graphite (372 mAhg-1). However, its theoretical reversible capacity is 644 mAhg-1 due to the conversion of SnS2 to Li2S and Sn in the first discharge. Furthermore, SnS2 can be processed using water as a solvent in place of previously mentioned NMP. This way, not only the electrochemical performance, but also the environmental friendliness, as well as costs during fabrication can be improved.This study focusses on the optimization of water-based slurry processing using SnS2 as active material, and water-soluble binders such as sodium carboxymethylcellulose (Na-CMC) and styrene butadiene rubber (SBR) in comparison to NMP-based electrodes using Polyvinyl difluoride (PVDF) as a binding agent.In this work, four different electrode compositions were investigated, namely SnS2/C45/CMC:SBR(1:1) in a 90/5/5 ratio and a 80/10/10 ratio, as well as a comparative system consisting of SnS2/C45/PVDF in the same ratios as the previous electrode. All electrode compositions showed an initial specific capacity of ~550 mAh/g, however the cycling stability was in the order of H2O-80:10:10 > H2O-90:5:5 > NMP-80:10:10 > NMP-90:5:5 (Figure 1), with the best water-based electrodes reaching 80% state-of-health (SoH) after 200 cycles.In order to understand the degradation mechanisms occurring during cycling and to elucidate the impact of H2O- and NMP-based processing on electrochemical performance, techniques such as Raman, SEM, XRD, XPS, and EIS were performed on pristine electrodes, on electrodes after first discharge (formation cycle), as well as on samples at 80% SoH. Furthermore, in-situ dilatometry was conducted to measure the linear change in length of the electrodes in the direction perpendicular to the electrode surface during cycling. Changes in crystal structure, morphology, surface chemistry (i.e. SEI formation), interface and charge transfer resistance, and volume expansion were correlated with the electrochemical performance.(Attached: Figure 1: Comparative graph of galvanostatic cycling with potential limitation (GCPL) of water- and NMP-based electrodes with varying ratios of active material/conductive agent/binder showing the development of capacity and coulombic efficiency as a function of cycle number) Figure 1

Tailoring Low‐Dimensional Perovskites Passivation for Efficient Two‐Step‐Processed FAPbI3 Solar Cells and Modules

AbstractConverting PbI2 residues into low‐dimensional perovskites through post‐treatment with ammonium‐based large cations can passivate 3D perovskites, thus has emerged as an effective strategy to improve the performance of perovskite solar cells (PSCs). Herein, a dramatically improved efficiency is demonstrated for PSCs based on a two‐step‐processed FAPbI3 perovskite via post‐treatment with formamidinium (FA)‐based benzamidine hydrochloride (PFACl), outperforming the commonly used methylamine (MA)‐based benzylamine hydrochloride (PMACl). With an in‐depth exploration of the crystal structures and morphology changes of the FAPbI3 perovskite upon the PFACl post‐treatment, the preferential formation of 1D rather than 2D structures on the 3D perovskite film is identified. In contrast to the 2D counterpart, the more energetically favorable 1D structure enables a more effective elimination of PbI2 residues. As a consequence, the PFACl‐induced 1D/3D perovskite film is endowed with smoother morphology, more uniform surface potential distribution, lower trap density, faster charge transfer, and better film stability than the PMACl‐induced 2D/3D perovskite and control films, demonstrating champion efficiencies of 24.9% for a small‐size PSC, 23.6% for a 1 cm2 large‐size PSC, and 21.2% for a 5 × 5 cm2 mini‐module, which is the highest among the perovskite solar mini‐modules using the two‐step deposition method.

The dynamic changes of mango (Mangifera indica L.) epicuticular wax during fruit development and effect of epicuticular wax on Colletotrichum gloeosporioides invasion.

Mango fruits are susceptible to diseases, such as anthracnose, during fruit development, leading to yield reduction. Epicuticular wax is closely related to resistance of plants to pathogenic bacterial invasion. In this study, the effect of mango fruit epicuticular wax on the invasion of Colletotrichum gloeosporioides was investigated, followed by to understand the changes of wax chemical composition and crystal morphology during mango fruit development using GC-MS and SEM. Results showed that the epicuticular wax of mango fruits can prevent the invasion of C. gloeosporioides, and 'Renong' showed the strongest resistance to C. gloeosporioides. The wax content of four mango varieties first increased and then decreased from 40 days after full bloom (DAFB) to 120 DAFB. In addition, 95 compounds were detected in the epicuticular wax of the four mango varieties at five developmental periods, in which primary alcohols, terpenoids and esters were the main wax chemical composition. Furthermore, the surface wax structure of mango fruit changed dynamically during fruit development, and irregular platelet-like crystals were the main wax structure. The present study showed the changes of wax content, chemical composition and crystal morphology during mango fruit development, and the special terpenoids (squalene, farnesyl acetate and farnesol) and dense crystal structure in the epicuticular wax of 'Renong' fruit may be the main reason for its stronger resistance to C. gloeosporioides than other varieties. Therefore, these results provide a reference for the follow-up study of mango fruit epicuticular wax synthesis mechanism and breeding.

Effects of comb-like poly-α-olefins on the cold flow properties of diesel fuel

Pour point depressants (PPDs) represent an efficient and economical approach to enhance diesel's low-temperature fluidity, yet their efficacy is influenced by molecular structure and surfactant moieties. To achieve highly effective PPDs, a series of comb-structured poly-alpha-olefins (PAOs) were synthesized in this paper, designated as 1-hexadecene-styrene (C16-SM), 1-hexadecene- allyl benzene (C16-AM), and 1-hexadecene-indene (C16-IM). The copolymers' impact on diminishing diesel's solid point (SP) and cold filter plugging point (CFPP) was thoroughly investigated. Notably, with a 1-hexadecene to styrene monomer molar ratio of 20:1, the most favorable inhibitory effect of C16-SM was observed, exhibiting a reduction of 10 °C for CFPP and 30 °C for SP. Comparing C16-SM to commercial pour point depressants (CPPDs) after subjecting them to an accelerated oxidation test revealed that the C16-SM performance was more stable under oxidative conditions. To address stability and environmental pollution concerns associated with PPDs, this study aims to develop a stable, eco-friendly PAO PPD and assess the influence of various benzene ring-based monomers on diesel's cold fluidity in low-temperature conditions. Furthermore, a novel mechanism elucidating the change in crystal morphology and size by PAOs is proposed.

Directional oxygen diffusion in Cu1.5Mn1.5O4 crystals for long reversible thermochemistry

Redox activity of metal oxides are the key to the development of high-temperature thermochemical energy storage. However, few studies have reported that the reactivity of metal oxides as thermochemical energy storage is significantly affected by the changes of crystal structure and morphology during redox, caused by ion diffusion and vacancy formation and migration. In this study, we find a previously unreported high-performance thermochemical energy storage material Cu1.5Mn1.5O4 with special structure. Cu1.5Mn1.5O4 shows high energy densities during reduction and oxidation (−219.852 and 207.618 kJ/kg), and keeps 97.06% and 92.98% reactivity after 600 cycles. Voids on specific surfaces are observed after cycling, but not in the fresh sample. We find the voids provide abundant Cu2+, Mn4+ species and lattice oxygen to promote its reaction performance. Cu ions migrate obviously after oxidation and molecular dynamics simulations reveal that DCu (7.4 × 10−14 cm2 s−1) is higher than DMn (5.1 × 10−14 cm2 s−1) and DO (1.7 × 10−14 cm2 s−1). Cu1.5Mn1.5O4 exhibits voids during oxidation due to ion transport described by the Kirkendall effect. In addition, DFT calculations verify that O2− is more easily to adsorb and diffuse on (111) surface, revealing the optimal transport path and directional diffusion mechanism of O2−. These mechanisms can provide ideas for the reasonable design of materials to improve thermochemical reaction performance.

Metal Work Function Effects on the Performance of UV–Visible–NIR Cs2SnI6 Photodetectors for Flexible Broadband Application

Herein, the role of top metal electrode work functions on the performance of flexible broadband ultraviolet (UV)–visible–near‐infrared (NIR) flexible Cs2SnI6 (CSI) photodetectors (PDs) are reported in the present study. The change in crystal plane orientation, surface morphology, and chemical composition of prepared films compared to hydrothermally synthesized CSI particles is confirmed by physical characteristics tools. The optical bandgap of CSI films is estimated to be 1.36 eV. The flexible CSI PDs are fabricated with three top metal electrodes (Mo, Ti, and Ni). The current–voltage (I–V) characteristics under the illumination of light sources with different wavelengths reveal the broadband UV–visible–NIR photodetection properties of flexible CSI PDs. The device with top Ti electrodes demonstrates maximum photoresponsivity (Rph = 1.65 ± 0.45 A W−1) and specific detectivity (Dph = 4.53 ± 0.36) × 1010 Jones for 455 nm compared to other wavelengths at Vb = 5 V. The fast photoresponse/decay time is 18 ms/24 ms for 455 nm at Vb = 1 V. The 85% and 90%–95% retentions of Rph of devices after 12 days keeping in a desiccator and after 500 bending cycle tests suggest the device's good environmental stability and mechanical flexibility, respectively. Thus, it is indicated in the results that CSI materials can be a potential candidate for flexible UV–visible–NIR photodetector for wearable electronic device applications.

Analysis of transverse elastic modulus and compressive deformation mechanism of cellulose crystals based on molecular dynamics

Cellulose nanocrystals (CNCs) have been widely used as reinforcing agents for composite materials due to their excellent mechanical properties. CNC composites are inevitably deformed by external forces during use. In order to reduce the damage of CNC composites in application and improve their service life, their mechanical properties and deformation mechanisms need to be studied in depth. In this study, cellulose Iβ crystals were selected for molecular dynamics simulation of nanoindentation to predict the transverse elastic modulus of cellulose crystals. The simulation results were compared with existing nanoindentation tests to verify the simulation accuracy. The impact of the loading depth, loading speed, and radius of the spherical indenter on elastic modulus and surface deformation of a system was explored. The results show that the loading depth and loading speed of the indenter have weak influence on the elastic modulus, and the small radius of the indenter (1 nm) will lead to the distortion of the elastic modulus. The compression deformation mechanism of cellulose crystal at the molecular level was analyzed by analyzing changes in cellulose crystal indentation morphology, molecular potential energy and hydrogen bond number during compression simulation. As the indenter radius and loading depth increase, the deformation degree of cellulose crystal also increases, whereas the loading speed within the 50–150 m/s range does not significantly influence on the deformation degree of cellulose crystal. These results may guide the production of nanocomposites with cellulose crystal reinforcements, which can be useful for preventing material damage and enhancing material efficiency.

Ultraviolet A-driven photoelectrochemical system for efficient manganese removal and recovery from contaminated water: Continuous deposition and accelerated dissolution

As the fourth most industrially applicable metal, the excessive manganese (Mn) mining and utilization generates an extensive quantity of Mn wastewater, leading to waste of valuable resource and numerous ecotoxicological effects. This study reported the novel photoelectrodeposition (PED) and photoassisted electrodissolution (PAED) processes driven by Ultraviolet A for Mn extraction and recycling from contaminated water. In the PED process with TiO2 nanorod arrays photoelectrode, efficient Mn removal above 83% was achieved over a wide pH range of 3–10, and selective removal of Mn2+ was achieved with Fe3+ coexistence. After deposition, Mn can be completely dissolved and recovered by the PAED process under acidic condition at pH 3. To the integration of the PED and PAED processes, 73.3 ± 0.9% of Mn can be recovered from the contaminated water with 20 mg/L Mn2+, and the energy consumption was 0.247 kWh/m3, which was only 63.5% of the conventional electrocatalysis process. The composite photocatalyst of TiO2-manganese oxides (TiO2-MnOx) film may form and develop on the electrode during the PED and PAED processes, accompanied by the Mn3+/Mn4+ redox cycle and the change in crystal morphology. As the predominant reactive species for Mn2+ oxidation, the continuous photogeneration of holes in the TiO2-MnOx film resulted in the continuous deposition of Mn. The mobile electrons photogenerated from the excited TiO2-MnOx film may also enhance the electron transfer and lead to the accelerated dissolution of Mn. The results of this study demonstrated that the PED-PAED process is an efficient and sustainable method for Mn removal and recovery.