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Aqueous zinc‐ion batteries are widely recognized as promising alternatives to lithium batteries due to their excellent safety, environmental compatibility, and cost‐effectiveness. Nonetheless, the formation of dendrites, corrosion, and undesirable side reactions on the zinc surface pose significant challenges to the cycling stability of zinc‐ion batteries. In this study, polar propylene carbonate (PC) is paired with tetrafluoroborate anions to establish a strong ion‐dipole interaction. Strong ion‐dipole interaction can not only alter the solvation structure of zinc ions but also facilitate the formation of a dynamic double electric layer on the surface of the zinc electrode, suppressing the formation of ZnF2 interface and carbonate, thereby facilitating uniform zinc ion deposition, and consequently improving battery cycling stability over a broad temperature range. Concretely, the formulated electrolyte enhances the cycling stability of the battery over a wide temperature range of −30 to 40 °C, accompanied by a capacity retention of ≈100% even after 10 000 cycles at −30 °C. The symmetrical battery utilizing this electrolyte exhibits stable cycling performance for over 1200 h at 25 °C and 1900 h at −30 °C, respectively. The findings provide a promising direction for the development of long‐cycle batteries capable of operating over a wide temperature range. [ABSTRACT FROM AUTHOR]

Organic lead halide perovskite solar cells (PSCs) have become a viable alternative for next‐generation photovoltaic systems. The significance of reproducibly processing perovskite with less defects comes from the fact that imperfections have a major impact on the solar cell's performance and long‐term stability. Although it is well known that cautious precursor processing has a significant influence on perovskite defect generation, there haven't been extensive investigations on the serial associations between precursor processing, perovskite orientation, and defect generation in PSCs. Making use of a unique precursor chemistry treatment technique that facilitates uniaxially oriented perovskite growth, it is aimed to mitigate defects of sequentially spin‐coated perovskite. Through the temperature‐dependent configurational entropic effect on coordination between iodoplumbate and dimethylsulfoxide (DMSO), a DMSO de‐intercalation processing method is developed. This method enables the induction of uniaxially‐oriented α‐FA0.9MA0.1PbI3‐xBrx (FA: formamidnium, MA: methylammomnium, x < 0.13) perovskite growth parallel to substrates. As a result, this processing delivered significant advances in power conversion efficiency (24.02%) and ambient operational stability under light. This straightforward technique provides a accesible process for producing efficient and stable perovskite solar cells, enabling uniaxially oriented perovskite fabrication without complicated procedures or additional substances. [ABSTRACT FROM AUTHOR]

Optical diamond materials are essential for infrared optical windows, microwave windows, and laser windows due to their exceptional properties. However, dark features inside the diamond are significant factors limiting optical properties, particularly at high deposition rates. This work focuses on adjusting crystallographic parameters to prepare (110) oriented optical-grade polycrystalline diamond films, aiming to mitigate dark features. Diamond films deposited via microwave plasma chemical vapor deposition (MPCVD) exhibit discernible quality stratification. Characterization analysis of diamond film samples with varying levels of black defects reveals a correlation: films with higher dark feature content tend to exhibit a preference for the (111) orientation, accompanied by a significant presence of penetration twins and interstitial voids. Conversely, transparent diamond films demonstrate a prominent (110) orientation, featuring numerous contact twins that alleviate competition from penetration twins and original grains during growth. Electron backscatter diffraction (EBSD) and scanning electron microscope (SEM) results reveal that transparent diamond films cultivated with a pronounced preference for the (110) orientation manifest consistent and seamless contact twins, leading to fewer dark features and improved optical transmittance. In contrast, (111) oriented diamond film exhibits numerous penetration twins, and holes form between them. Based on the analysis, 5-inch optical polycrystalline diamond films with (110) orientation were achieved successfully by suppressing dark features. [ABSTRACT FROM AUTHOR]

Fabricating highly oriented 2D nanosheet arrays is crucial for boosting their performance in electronics, catalysis, optics, and energy conversion, while it remains a challenge due to the high surface energy often leads to random aggregation or interlaced structure. In this study, it is found that the exposed facet of Fe2O3 can greatly influence the interface growth arrangement of bimetallic hydroxide (NiCo(OH)2) nanosheets. The NiCo(OH)2 nanosheets tend to parallel‐standing on the cubic and spindle Fe2O3 while random‐ and interlaced‐standing on the Fe2O3 hexagonal nanoplates and microspheres. The theoretical simulation further indicates the orientation of deposited hydroxide sheets is decided explicitly by the interfacial lattice match/mismatch. Compared to the common interlaced structure of nanosheets, the parallel‐standing nanosheet arrays reduce grain boundaries and improve the charge transfer efficiency. As a result, the derived NiCoP cages exhibit a promising oxygen evolution reaction performance with an overpotential of 255 mV at 10 mA cm−2, and the maximum current density of 400 mA cm−2 with the overpotential of 319 mV. [ABSTRACT FROM AUTHOR]

Realizing durative dense, dendrite‐free, and no by‐product deposition configuration on Zn anodes is crucial to solving the short circuit and premature failure of batteries, which is simultaneously determined by the Zn interface chemistry, electro‐reduction kinetics, mass transfer process, and their interaction. Herein, this work unmasks a domino effect of the β‐alanine cations (Ala+) within the hydrogel matrix, which effectively triggers the subsequent electrostatic shielding and beneficial knock‐on effects via the specifical adsorption earliest event on the Zn anode surface. The electrostatic shielding effect regulates the crystallographic energetic preference of Zn deposits and retards fast electro‐reduction kinetics, thereby steering stacked stockier block morphology and realizing crystallographic optimization. Meanwhile, the mass transfer rate of Zn2+ ions was accelerated via the SO42− anion immobilized caused by Ala+ in bulk electrolyte, finally bringing the balance between electroreduction kinetics and mass transfer process, which enables dendrite‐free Zn deposition behavior. Concomitantly, the interfacial adsorbed Ala+ cations facilitate the electrochemical reduction of interfacial SO42− anions to form the inorganic‐organic hybrid solid electrolyte interphase layer. The above domino effects immensely improve the utilization efficiency of Zn anodes and long‐term stability, as demonstrated by the 12 times longer life of Zn||Zn cells (3650 h) and ultrahigh Coulombic efficiency (99.4 %). [ABSTRACT FROM AUTHOR]

The precise control and understanding of crystal orientation in perovskite polycrystalline films are crucial for the development of efficient and stable devices. However, achieving this control remains a significant challenge. Herein, a PbI2 oriented growth strategy is developed, combined with in situ vapor–solid reaction transformations, to achieve oriented growth of full‐vacuum perovskite films. Grazing‐incidence wide‐angle X‐ray scattering (GIWAXS) analysis revealed the general pattern of PbI2 oriented vapor growth and in situ vapor–solid reaction transformation in this two‐step process. The resulting preferred orientation has effectively reduced trap state density, optimizing the carrier dynamics. As a result, champion efficiencies of 22.11% (0.148 cm2), 20.60% (1 cm2), and 19.41% (5 × 5 cm2 mini‐modules) are achieved, which are the highest value for perovskite based on vapor–solid reaction. Additionally, the oriented growth method is applicable to a variety of guide layers and is extended to 30 × 30 cm2 film, demonstrating the universality and scalability of the method. [ABSTRACT FROM AUTHOR]

Zn deposition with a surface‐preferred (002) crystal plane has attracted extensive attention due to its inhibited dendrite growth and side reactions. However, the nucleation and growth of the Zn(002) crystal plane are closely related to the interfacial properties. Herein, oriented growth of Zn(002) crystal plane is realized on Ag‐modified surface that is directly visualized by in situ atomic force microscopy. A solid solution HCP‐Zn (~1.10 at. % solubility of Ag, 30 °C) is formed on the Ag coated Zn foil (Zn@Ag) and possesses the same crystal structure as Zn to reduce its nucleation barrier caused by their lattice mismatch. It merits oriented Zn deposition and corrosion‐resistant surface, and presents long cycling stability in symmetric cells and full cells coupled with V2O5 cathode. This work provides insights into interfacial regulation of Zn anodes for high‐performance aqueous zinc metal batteries. [ABSTRACT FROM AUTHOR]

A controlled growth of two‐dimensional (2D) π‐conjugated metal‐organic frameworks (MOFs) on solid substrates can open exciting opportunities for the application of 2D MOFs as optoelectronic devices. Some factors like solvent composition and type of substrates are known to influence the properties of solution‐processed 2D MOF crystals; however, a mechanistic understanding of how interactions between solvent, substrate, and precursors affect heterogeneous nucleation has been limited. Here, it is reported that the structure of Ni‐catecholate (Ni‐CAT‐1) MOFs at a solid–liquid interface is controlled by solvent–substrate and solvent–MOF precursor interactions. Specifically, the structure of the MOF film can be controlled by varying the affinity of the solvent to the substrate. As a fraction of N,N‐dimethylformamide (DMF) in a binary solvent mixture of water and DMF increases, the arrangement of Ni‐CAT‐1 crystals varies from vertically aligned nanorods to the graphite substrate to less ordered nanorods with the lower initial nucleation number density of Ni‐CAT‐1 crystals on the surface. [ABSTRACT FROM AUTHOR]

Dendrite‐free Zn anode is the key to avoiding battery failure, which is largely determined by the crystal growth during the electrodeposition process. Therefore, controlling the specific crystal orientation growth of Zn is imperative for high‐performing aqueous zinc ion batteries. Herein, an electrocrystallization orientation regulation strategy is proposed to achieve near‐unity stacked Zn (002) texture growth. Featuring the zincophilic nature and high electronegative carboxylate radical, disodium maleate molecules tend to selectively adsorb on the Zn (002) crystal plane, forming a dynamic protection layer. This adsorption layer regulates Zn2+ diffusion along [100] and [101] orientations with the lowest deposition rate on the (002) plane, homogenizes Zn2+ flux, and keeps away water from Zn surface, constructing the flattened and horizontally arranged Zn deposition layer with dominantly Zn (002) texture and inhibited side‐reaction. Consequently, the Zn anode with near‐unity stacked (002) texture exhibits a 40‐fold enhancement in running lifetime beyond 3200 h and improved coulombic efficiency of 99.81% over 3000 cycles than that with bare ZnSO4 electrolyte. Even at harsh plating/stripping conditions of 30 and 30 mAh cm−2, the Zn anode still sustains state‐of‐the‐art stability over 120 h, enabling a substantial advance in the long‐term stability of the battery. [ABSTRACT FROM AUTHOR]

Boron-mullites are potential candidate crystal phases for broadband near-infrared (NIR) luminescence in the mullite series due to their higher complexity in crystal structure and abundant [AlO 6 ] units for accommodating transition metal ions as luminescence activators. In this work, the effect of ZrO 2 and TiO 2 on the microstructure and NIR luminescent properties of mullite type Cr3+:Al 4 B 2 O 9 glass ceramics were analyzed in detail. Through characterizations including XRD, SEM, TEM and NMR, the oriented growth of strip-shaped grains in ZrO 2 doped glass ceramic samples has been verified. The proportion of [AlO 6 ] units is strongly correlated with NIR spectra, suggesting that the strategy for modulation the NIR luminescence through oriented growth can be generalized as a universal method for manipulation of the optical properties for transition metal ion activated crystals with the mullite type structure. [ABSTRACT FROM AUTHOR]

[Display omitted] Amorphous inorganic solids are traditionally isotropic, thus, it is believed that they only grow in a non-preferential way without the assistance of regulators, leading to the morphologies of nanospheres or irregular aggregates of nanoparticles. However, in the presence of (ortho)phosphate (Pi) and pyrophosphate ions (PPi) which have synergistic roles in biomineralization, the highly elongated amorphous nanowires (denoted ACPPNs) form in a regulator-free aqueous solution (without templates, additives, organics, etc). Based on thorough characterization and tracking of the formation process (e.g., Cryo-TEM, spherical aberration correction high resolution TEM, solid state NMR, high energy resolution monochromated STEM-EELS), the microstructure and its preferential growth behavior are elucidated. In ACPPNs, amorphous calcium orthophosphate and amorphous calcium pyrophosphate are distributed at separated but close sites. The ACPPNs grow via either the preferential attachment of ∼2 nm nanoclusters in a 1-dimension way, or the transformation of bigger nanoparticles, indicating an inherent driving force-governed process. We propose that the anisotropy of ACPPNs microstructure, which is corroborated experimentally, causes their oriented growth. This study proves that, unlike the conventional view, amorphous minerals can form via oriented growth without external regulation, demonstrating a novel insight into the structures and growth behaviors of amorphous minerals. [ABSTRACT FROM AUTHOR]

Purposes Metal-organic framework (MOF) membranes have been extensively studied in recent years owing to their rich porosity as well as their uniform and adjustable pore size. Still, the preparation of ultra-thin and defect-free MOF membranes faces great challenges. Controlling the growth orientation of the MOF membranes helps reduce intergranular defects and optimize membrane thickness. Methods For the first time, an ultra-thin and oriented UTSA-280 MOF membrane is prepared on a porous substrate via a polydopamine (PDA) interface layer-mediation strategy. The PDA layer provides abundant adsorption and anchoring sites for UTSA-280 through multiple interactions with metal ions to facilitate the heterogeneous nucleation and growth of UTSA-280. Furthermore, the nucleation density and growth rate can be controlled through varying PDA deposition amounts to modulate the growth orientation of MOF crystals and membrane thickness. Findings Finally, a (202)-oriented UTSA-280 MOF membrane prepared under optimal conditions with a membrane thickness of 162 nm achieves H2 permeance up to 4 141.8 GPU and H2/CO2 separation selectivity of 18.5, far exceeding the Robeson upper bound in 2008.

Abstract A controlled growth of two‐dimensional (2D) π‐conjugated metal‐organic frameworks (MOFs) on solid substrates can open exciting opportunities for the application of 2D MOFs as optoelectronic devices. Some factors like solvent composition and type of substrates are known to influence the properties of solution‐processed 2D MOF crystals; however, a mechanistic understanding of how interactions between solvent, substrate, and precursors affect heterogeneous nucleation has been limited. Here, it is reported that the structure of Ni‐catecholate (Ni‐CAT‐1) MOFs at a solid–liquid interface is controlled by solvent–substrate and solvent–MOF precursor interactions. Specifically, the structure of the MOF film can be controlled by varying the affinity of the solvent to the substrate. As a fraction of N,N‐dimethylformamide (DMF) in a binary solvent mixture of water and DMF increases, the arrangement of Ni‐CAT‐1 crystals varies from vertically aligned nanorods to the graphite substrate to less ordered nanorods with the lower initial nucleation number density of Ni‐CAT‐1 crystals on the surface.

The application of self‐assembled molecules (SAM) allows inverted‐structural perovskite solar cells to accomplish high efficiencies, by virtue of their high hole conductivity and negligible parasitic absorption. However, amphiphilic SAM tend to form spherical micelles in commonly used alcoholic solvents, leading to aggregation in the resulting film. In addition, hydrophobic groups of SAM are exposed to the surroundings after being deposited on transparent substrates, responsible for the poor crystallinity of perovskite and interface quality. Therefore, it is important to study the treatment of SAM layers or SAM/perovskite interfaces for better device performance. Herein, dual regulation of SAM and perovskite is achieved via a facile posttreatment by formamidinium chloride (FACl) solution in N,N‐Dimethylformamide. First, by taking advantage of solvent rinsing, aggregations at the surface of SAM layer are alleviated. Second, FACl on the top of the SAM layer assists the crystallization of perovskite through interaction with PbI2 and reduces the defect concentration via passivating the halide vacancies at the buried interface of the device. With a more uniform SAM layer, better‐crystallized perovskite, and suppressed nonradiative recombination between them, the power conversion efficiency of the target device is improved by 20%. [ABSTRACT FROM AUTHOR]

Understanding the mechanism of the oriented growth in multi-component alumina-based fibers and inhibiting its progression is crucial for enhancing their thermal stability. In this study, a novel diphasic fiber composed of lamellar α-Al 2 O 3 and mosaic-like mullite grains was prepared. We discussed the oriented growth behavior of lamellar α-Al 2 O 3 grains and the diffusion phenomenon of the Al element in SiO 2 substrate under the combined addition of iron sol and La 2 O 3 , proposing a new mechanism for oriented growth in diphasic fibers. The diffusion of the Si element to the tips of alumina grains contributed to a significant increase in the mobility of non-basal planes, resulting in (0001) surface growth of α-Al 2 O 3 grains. Furthermore, the La segregation at grain boundaries significantly impeded the oriented growth of α-Al 2 O 3 grains, which was critical for improving the thermal stability of multiphase alumina-based fibers. [ABSTRACT FROM AUTHOR]

The development of neural tissue engineering has brought new hope to the treatment of spinal cord injury (SCI). Up to date, various scaffolds have been developed to induce the oriented growth and arrangement of nerves to facilitate the repair after injury. In this work, a conductive and anisotropic inverse opal substrate was presented by modifying polystyrene (PS) inverse opal films with carbon nanotubes and then stretching them to varying degrees. The film had good biocompatibility, and neural stem cells (NSCs) grown on the film displayed good orientation along the stretching direction. In addition, benefiting from the conductivity and anisotropy of the film, NSCs differentiated into neurons significantly. These results suggest that the conductive and anisotropic PS inverse opal substrates possess value in nerve tissue engineering regeneration.

Defect engineering is considered an effective method to adjust the photocatalytic properties of materials. In this work, we synthesized the vacancy-rich ZnO rods with (100) planes via the melamine-assisted thermal activation method. A high concentration of oxygen vacancies was successfully introduced into non-polar oriented ZnO rods by calcination. The effect of oxygen vacancy on the photocatalytic properties of non-polar-oriented ZnO rods was investigated. Raman and XPS spectra revealed the formation of oxygen vacancies in the ZnO. The results showed that the growth habit and defects in ZnO can be controlled by changing the ratio of ZnO to melamine. The higher ratio of ZnO to melamine led to more amounts of (100) planes and oxygen vacancies in ZnO, and it reached the highest when the ratio was 1.2:1. When the ratio was 1.2:1, ZnO exhibited a high methyl orange degradation rate (95.8%). The differences in oxygen vacancy concentration and non-polar planes were responsible for the improvement in photocatalytic performance. ZnO exhibited good stability and regeneration capacity. After recycling four times, the degradation rate was still at 92%. Using the same method, vacancy-rich α-Fe2O3 was obtained. This work could offer a new and simple strategy for designing a photocatalyst with oxygen vacancies. [ABSTRACT FROM AUTHOR]

Anion doping is an efficient method for modifying the electrical property of the p‐type semiconductor CuI. However, adjustment of the hole density is still challenging. Using sputtering and spin coating techniques, well‐controlled S‐doping of CuI thin films has been realized. The spin‐coated samples present a single (111) out‐of‐plane orientation and very high crystallinity, which is comparable with previously reported epitaxial CuI thin films. The sputtered thin films have advantages in surface morphology and conductivity. Substituting S for I can achieve efficient acceptor doping of CuI for both the physical and chemical growth methods. The highest conductivity of CuI appears at 2.0 at% of S doping, and the doping efficiency is influenced by the self‐compensation effect. [ABSTRACT FROM AUTHOR]

Experimental results of microstructural studies of refractory nickel alloys obtained by selective laser melting under different crystallization conditions are systematized. The dendritic (cellular) structure and the distribution of the alloying elements in the volume of dendrite arms are studied by scanning and transmission electron microscopy. The detected microsegregation matches a normal crystallization law and is caused by concentration supercooling. It is shown that the main factors responsible for formation of the fine structure of a track are the orientation growth (epitaxy) and the competitive growth of crystallites. The orientation of the crystallites is transferred not only by the first-order arms but also by the second-order arms, and a specific direction is implemented upon coincidence of the crystallographic orientation of the crystallite with the radial direction of the heat removal. The increasing complexity and the fragmentation of the fine structure are associated with the mechanism of stochastic binarization of the crystallographic orientation implemented upon partial remelting and opening of fragments of cells in the current and preceding layers. [ABSTRACT FROM AUTHOR]

Abstract A multistep deposition technique is developed to produce highly oriented diamond films by hot filament chemical vapor deposition (HFCVD) on Si (111) substrates. The orientation is produced by use of a thin, 5–20 nm, Ni interlayer. Annealing studies demonstrate diffusion of Ni into Si to form nickel silicides with crystal structure depending on temperature. The HFCVD diamond film with Ni interlayer results in reduced non-diamond carbon, low surface roughness, high diamond crystal quality, and increased texturing relative to growth on bare silicon wafers. X-ray diffraction results show that the diamond film grown with 10 nm Ni interlayer yielded 92.5% of the diamond grains oriented along the (110) crystal planes with ~ 2.5 µm thickness and large average grain size ~ 1.45 µm based on scanning electron microscopy. Texture is also observed to develop for ~ 300 nm thick diamond films with ~ 89.0% of the grains oriented along the (110) crystal plane direction. These results are significantly better than diamond grown on Si (111) without Ni layer with the same HFCVD conditions. The oriented growth of diamond film on Ni interlayers is explained by a proposed model wherein the nano-diamond seeds becoming oriented relative to the β1-Ni3Si that forms during the diamond nucleation period. The model also explains the silicidation and diamond growth processes. Article Highlights High quality diamond film with minimum surface roughness and ~93% oriented grains along (110) crystallographic direction is grown on Si substrate using a thin 5 to 20 nm nickel layer. A detailed report on the formation of different phases of nickel silicide, its stability with different temperature, and its role for diamond film texturing at HFCVD growth condition is presented. A diamond growth model on Si substrate with Ni interlayer to grow high quality-oriented diamond film is established.

Two‐dimensional (2D) conductive metal‐organic frameworks (MOF) represent a unique class of electrode materials with high capacity and power density. Understanding molecular mechanisms and pathways for heterogeneous nucleation of 2D π‐conjugated MOFs is highly desirable for controlling the structure and properties of conductive MOFs on solid substrates. Herein, a systematic study of nucleation and growth of 2D π‐conjugated Ni‐catecholate (Ni‐CAT‐1) MOFs on highly oriented pyrolytic graphite (HOPG) and copper substrates is reported. It is discovered that the nucleation density and growth kinetics of the MOF film can be controlled by varying substrate interactions with the organic linker. Specifically, π–π interactions between the linker and the HOPG dictate lower nucleation density, whereas π–metal interactions between the linker and the copper substrate dictate faster nucleation and higher nucleation densities. These studies reveal the key mechanism for Ni‐CAT‐1 nucleation on different surfaces and provide insights into interfacial control over the growth of other 2D π‐conjugated MOF films on solid substrates to inform synthesis of functional materials. [ABSTRACT FROM AUTHOR]

The inverted perovskite solar cell has made great progress in recent years and the quality of the heterojunction has played a key role. Here, a series of halide‐substituted benzoic acid molecules are investigated as the bridge between nickel oxide and the perovskite, constructing a stable and efficient buried heterojunction via halogen bonding. The designed molecules are anchored at the surface of NiO by the coordination between the carboxyl and hydroxyl groups. On the opposite site of the molecules, strong halogen bonding is formed by binding the undercoordinated I− at the buried surface of the perovskite, which inhibits the generation of I2 under continuous light soaking and thereby suppresses the formation of voids. Moreover, the highly directional halogen bonding is beneficial for the oriented growth of perovskite crystals, which accelerate the carrier transport. As a result, the champion device yields a power conversion efficiency (PCE) of 22.02% and the encapsulated device maintains 91.86% of the initial PCE under continuous 1‐sun illumination at 55 °C for 1000 h. [ABSTRACT FROM AUTHOR]

Abstract Two‐dimensional (2D) conductive metal‐organic frameworks (MOF) represent a unique class of electrode materials with high capacity and power density. Understanding molecular mechanisms and pathways for heterogeneous nucleation of 2D π‐conjugated MOFs is highly desirable for controlling the structure and properties of conductive MOFs on solid substrates. Herein, a systematic study of nucleation and growth of 2D π‐conjugated Ni‐catecholate (Ni‐CAT‐1) MOFs on highly oriented pyrolytic graphite (HOPG) and copper substrates is reported. It is discovered that the nucleation density and growth kinetics of the MOF film can be controlled by varying substrate interactions with the organic linker. Specifically, π–π interactions between the linker and the HOPG dictate lower nucleation density, whereas π–metal interactions between the linker and the copper substrate dictate faster nucleation and higher nucleation densities. These studies reveal the key mechanism for Ni‐CAT‐1 nucleation on different surfaces and provide insights into interfacial control over the growth of other 2D π‐conjugated MOF films on solid substrates to inform synthesis of functional materials.

Metal–organic frameworks (MOFs) are porous structures that possess high specific surface areas, making them promising cathode materials for energy storage devices. However, solving the problems of random growth and easy aggregation of MOF nanosheets remains a challenge. In this study, hydrothermal and calcination methods were used to successfully create nickel cobalt molybdenum metal oxide (NCMO) nanoflowers, followed by the directional growth of NiCo–MOF on its surface. The oriented growth of NiCo–MOF nanosheets on NCMO nanospheres effectively prevented agglomeration, forming NCMO@NiCo–MOF with enhanced electrochemical sensitivity and a large quantity of active sites. When used as an electrode, NCMO@NiCo–MOF forms a large contact area with the electrolyte, demonstrating a high specific capacitance of 1724 F g−1 at a current density of 1 A g−1. Furthermore, at a power density of 824.8 W kg−1, an asymmetric supercapacitor constructed from NCMO@NiCo–MOF and activated carbon exhibited a high energy density of 44.5 Wh kg−1. This study presents a facile method for the assembly of MOF nanosheets for three-dimensional supercapacitors. [Display omitted] • Mixed metal oxide nanomaterials exhibit synergistic enhancement effects. • NCMO nanospheres are prepared via hydrothermal and calcination methods. • Ultrathin NiCo metal–organic framework is grown on the NCMO nanosphere surface. • The NCMO@NiCo–MOF demonstrates a high specific capacitance of 1724 F g−1 at 1 A g−1. [ABSTRACT FROM AUTHOR]

Optimal orientation is the key factor to optimize the gas separation performance of metal-organic framework (MOF) membranes. However, it is still greatly challenging to prepare large-area oriented MOF membranes for industrial applications. Herein, we prepared compact and (100) oriented zeolitic-imidazolate framework-8 (ZIF-8) membranes with membrane area up to 500 cm2 on the graphite substrate via support-induced strategy within 2 h. With membrane thickness of only 620 nm, the (100) oriented ZIF-8 membranes exhibit high gas separation performances due to the reduction of inter-crystalline defects and permeation resistance. At 100 °C and 1 bar, the separation factors of H 2 /CO 2 , H 2 /CH 4 and H 2 /C 3 H 8 are 18.5, 58.2 and 101.6, respectively, with H 2 permeance of about 160 x 10−9 mol m−2 s−1·Pa−1. The different positions of the 500 cm2 ZIF-8 membrane show complete consistency in orientation and separation performance, recommending this membrane suitable for future industrial applications. Further, also oriented ZIF-67 and MOF-303 membranes can be consistently prepared by this strategy, confirming its versatility for the preparation of large-area MOF membranes. [Display omitted] • Compact and (100) oriented ZIF-8 membranes are prepared on the graphite substrate via support-induced strategy. • The membrane area of the (100) oriented ZIF-8 membrane is up to 500 cm2. • The oriented ZIF-8 membrane displays high hydrogen permselectivity due to the reduction of inter-crystalline defects. • At 100 °C and 1 bar, the separation factors of H 2 /CO 2 , H 2 /CH 4 and H 2 /C 3 H 8 are 18.5, 58.2 and 101.6 for the ZIF-8 membrane. [ABSTRACT FROM AUTHOR]

A comparative study of the synthesis of TiO2 nanorods on fluorine‐doped tin oxide (FTO) glass, Si, SiO2, Si/Ta, Si/TiN, Si/TiN/Ti and Si/HFO2 substrates by hydrothermal reaction is presented. Detailed analysis on the growth of TiO2 on pre‐annealed Si/TiN/Ti and HfO2 (HFO) surfaces is also given. For Si/TiN/Ti, a pre‐annealing procedure led to the transformation of Ti to a TiO2 layer which acts as a seed for aligned growth of TiO2 nanorods. In contrast, Si/HFO does not provide a nucleation site for the formation of aligned nanorods. Various samples were prepared by varying the synthesis conditions, i.e. pre‐ and post‐annealing temperatures and hydrothermal reaction time to figure out the optimum conditions which lead to unidirectional and highly aligned nanorods. X‐ray diffraction, scanning electron microscopy, ultraviolet–visible spectroscopy and Raman spectroscopy were used to study structural, morphological and optical properties of synthesized samples. It is found that TiO2 nanorods exhibit a rutile phase on the Si/Ti/TiN and Si/HFO substrates, but highly oriented vertical growth of nanorods has been observed only on pre‐annealed Si/TiN/Ti substrates. On the other hand, TiO2 nanorods form dandelion‐like structures on Si/HFO substrates. Growth of vertically oriented TiO2 nanorods on Si/TiN/Ti is attributed to the TiO2 seed layer which forms after the process of pre‐annealing of substrates at a suitable temperature. Variation in hydrothermal reaction time and post‐annealing temperature brings further improvement in crystallinity and morphology of nanorods. This work shows that the pre‐annealed Si/TiN/Ti substrate is the optimal choice to achieve vertically oriented, highly aligned TiO2 nanorods. [ABSTRACT FROM AUTHOR]

Developing efficient oxygen evolution reaction (OER) catalysts for electrochemical water splitting is still a challenge. In this work, we put forward a strategy combining oriented growth of metal organic framework and high-temperature ammonization to synthesize cobalt nanoparticles (Co NPs) encapsulated in nitrogen-doped carbon skeleton. The optimized CoBDC-NF-NH3-650 exhibits an outstanding OER activity with an onset potential of 1.48 V (vs. RHE), and an overpotential of 345 mV at a current density of 10 mA cm−2. Importantly, the CoBDC-NF-NH3-650 possesses an outstanding stability with negligible potential attenuation after 60 h continuous electrolysis. Experimental results reveal that edge carbon defects and the synergistic effect between Co NPs and N-doped carbon attribute to the impressive OER activity of CoBDC-NF-NH3-650. [ABSTRACT FROM AUTHOR]

Organic electronic devices rely on the performance of polymers that are used as active layers. Poly-(3,4-ethylenedioxythiophene) (PEDOT) is one of the most studied polymers for organic electronic devices and especially bioelectronics. Because charge carriers move along the polymer backbone (anisotropic charge transport), one of the key challenges is controlling orientation of the polymer in thin films, hence increasing the transport performance. Here, we introduce a method for the oriented growth of PEDOT chains on nanometer-thick self-assembled monolayer (SAM)-modified gold electrodes. We show that, when the gold layer is covered with a SAM that is active for polymer chain growth, a more crystalline film is obtained compared to the surface having a nonactive SAM. We used a nitric acid oxidant to perform the polymerization, which overcomes temperature incompatibility between the gold-supported thiolate monolayers and the polymerization. We characterize the chemical nature and physical properties of the oriented PEDOT film. Reaction conditions and ease of processing appeal especially to organic electronic device applications where surface modification can play a critical role. [ABSTRACT FROM AUTHOR]

Neural stem cell therapy has become a promising cure in the treatment of neurodegenerative disorders. Owing to the anisotropy of the nervous system, the newly derived neurons need not only the functional integrity but also the oriented growth to contact with the partner cells to establish functional connections. So the oriented growth of the newly derived neurons is a key factor in neural stem cell–based nerve regeneration. Nowadays, various biomaterials have been applied to assist in the oriented growth of neural stem cell–derived neurons. However, among these biomaterials, the magnetic materials applied in guiding the neuronal growth are still fewer than the other materials, such as the fibers. So in this work, we developed the magnetic nanochains to guide the oriented growth of neural stem cell–derived neurons. With the guidance of the magnetic nanochains, the seeded neural stem cells exhibited a good arrangement, and the neural stem cell–derived neurons showed well-oriented growth with the orientation of the nanochains. We anticipated that the magnetic nanochains would have huge potential in stem cell–based nerve regeneration.

Although quasi-two-dimensional (quasi-2D) perovskites are ideal material platforms for highly efficient linearly polarized electroluminescence owing to their anisotropic crystal structures, so far, there has been no practical implementation of these materials for the demonstration of linearly polarized perovskite light-emitting diodes (LP-PeLEDs). This scarcity is due to difficulty in orientation and phase distribution control of the quasi-2D perovskites while minimizing the defects, all of which are required to manifest aligned transition dipole moments (TDMs). To achieve this multifaceted goal, herein, we introduce a synergistic strategy to quasi-2D perovskites by incorporating both a trimethylolpropane triacrylate anchoring layer and 18-Crown-6 molecular passivator into the film fabrication process. It is found that the interfacial anchoring layer guides the oriented growth of perovskites along the (110) plane, whereas the molecular passivator reduces the number of defects and homogenizes the crystal phase. As a result, a quasi-2D perovskite film with macroscopically aligned TDM that renders high radiative recombination and the degree of linear polarization (DoLP) is constructed. This "coherence-programmed emission layer" demonstrates highly efficient LP-PeLEDs, not only achieving a maximum external quantum efficiency of ∼23.7%, a brightness of ∼36,142 cd/m 2 , and a DoLP of ∼38%, but also significantly improving the signal-to-interference-and-noise ratio in a multi-cell visible light communication system.

Highly (001)‐oriented pure‐phase BFO films were prepared on traditional Si substrates via radio frequency magnetron sputtering (RFMS). The crystallinity of the films is found to be increased, that is, higher degree of (001) texture, larger grain size, less grain boundary, denser surface morphology, and better thickness uniformity, with increased film thickness. These factors have significant influences on the electrical properties of BFO films, that is, dielectric response, as well as ferroelectric polarization and leakage current characteristics. The 240‐nm‐thick film exhibits relatively poor electrical properties compared with other three thicker films, which is mainly due to its small grain, the enhancement of the clamping effect of neighboring grains, and the absence of domain walls. The essential roles of the evolution and distribution of grains/domains and defect charges in leakage mechanism and ferroelectric switching polarization were also investigated systematically. It was found that 600‐nm‐thick BFO film has the lowest leakage current density (as low as 1.8 × 10−6 A / cm2 @ 90 kV/cm) and followed a mixed SE or SCLC conduction behavior, while the leakage behavior in other films is dominated by SE and P‐F currents. All (001)‐BFO films have a giant electrical polarization which is solely originated from the contribution of ferroelectric domain switching, and it has lower switching voltage and faster switching rate in thicker films. [ABSTRACT FROM AUTHOR]

Metal–organic framework membranes are usually prepared by in situ or secondary growth in a solution/hydrogel. The use of organic solvents may cause safety and environmental problems and produce solvent‐induced defects. Here, highly oriented and permselective ZIF‐95 membranes are prepared for the first time via a solvent‐free secondary growth method. The solvent‐free growth is not only helpful to control the membrane microstructure and thickness, but also to reduce the intercrystalline defects. In case of solvent‐free growth, a perfectly oriented structure leads to an outstanding reduction of intercrystalline defects and transport resistances. For the separation of equimolar binary gas mixtures by using the highly oriented ZIF‐95 membrane at 25 °C and 1 bar, the mixture separation factors of H2/CO2 and H2/CH4 are 184 and 140, respectively, with H2 permeance of over 1.9×10−7 mol m−2 s−1 Pa−1 which are much higher than those of the randomly oriented ZIF‐95 membrane. [ABSTRACT FROM AUTHOR]

Enhanced polarization emerges as a potent strategy for further enhancing the photocatalytic performance of a photocatalyst. Considering the anisotropy of ferroelectric polarization and the improvement of polarization by defects, [010] preferred growth Bi 4 Ti 3 O 12 nanowires with oxygen vacancies were prepared via a hydrothermal method. Bi 4 Ti 3 O 12 nanowires exhibited a photocatalytic NO removal efficiency of up to 67.5% under visible light irradiation (λ > 420 nm), which is much higher than that of its counterpart, Bi 4 Ti 3 O 12 (3%). Structural characterizations and theoretical calculations support that, the engineering of oxygen vacancies in Bi 4 Ti 3 O 12 can enhance the polarization in the [010] and [100] directions, and gradually shifted the polarization dominant direction of Bi 4 Ti 3 O 12 from [100] to [010]. Overall, the improved polarization and generated oxygen vacancies enhanced the photocatalytic NO removal performance of Bi 4 Ti 3 O 12 nanowires. This work elucidates the significance of rational engineering oxygen vacancy-based microstructures and utilizing the polarization to amplify the photocatalytic performance. [Display omitted] • The [010] oriented Bi 4 Ti 3 O 12 nanowires was synthesized by a hydrothermal method. • DFT calculations evidenced oxygen vacancies improvd the polarization of Bi 4 Ti 3 O 12. • Oxygen vacancies shifted polarization direction of Bi 4 Ti 3 O 12 from [100] to [010]. • The improved photocatalytic NO removal was due to oxygen vacancies and polarization. [ABSTRACT FROM AUTHOR]

Abstract The potential of metal–organic frameworks (MOFs) for applications in optoelectronics results from a unique combination of interesting photophysical properties and straightforward tunability of organic and inorganic units. Here, it is demonstrated that using MOF approach chromophores can be assembled into well‐ordered 1D arrays using metal‐oxo strands as lead structure, and the resulting porphyrinic rows exhibit unique photophysical properties and allow the realization of highly sensitive photodetectors. A porphyrinic MOF thin film, In‐TCPP surface‐coordinated MOF thin films with [021] orientation is fabricated using a layer‐by‐layer method, from In(NO3)3 and TCPP (5,10,15,20‐(4‐carboxyphenyl)porphyrin). Detailed experimental and theoretical analysis reveals that the assembly yields a structure where In‐oxo strands running parallel to the substrate fix the chromophoric linkers to yield 1D arrays of porphyrins. The frontier orbitals of this highly anisotropic arrangement are localized in these columnar arrangements of porphyrins and result in high photoactivity, which is exploited to fabricate a photodetector with record (as compared to other organic materials) responsivity in visible regime of 7.28 × 1014 Jones and short rise/fall times (0.07/0.04 s). This oriented MOF thin film‐based high‐sensitive photodetector provides a new avenue to use inorganic, stable lead structures to assemble organic semiconductors into regular arrays, thus creating a huge potential for the fabrication of optoelectronic devices.

The potential of metal–organic frameworks (MOFs) for applications in optoelectronics results from a unique combination of interesting photophysical properties and straightforward tunability of organic and inorganic units. Here, it is demonstrated that using MOF approach chromophores can be assembled into well‐ordered 1D arrays using metal‐oxo strands as lead structure, and the resulting porphyrinic rows exhibit unique photophysical properties and allow the realization of highly sensitive photodetectors. A porphyrinic MOF thin film, In‐TCPP surface‐coordinated MOF thin films with [021] orientation is fabricated using a layer‐by‐layer method, from In(NO3)3 and TCPP (5,10,15,20‐(4‐carboxyphenyl)porphyrin). Detailed experimental and theoretical analysis reveals that the assembly yields a structure where In‐oxo strands running parallel to the substrate fix the chromophoric linkers to yield 1D arrays of porphyrins. The frontier orbitals of this highly anisotropic arrangement are localized in these columnar arrangements of porphyrins and result in high photoactivity, which is exploited to fabricate a photodetector with record (as compared to other organic materials) responsivity in visible regime of 7.28 × 1014 Jones and short rise/fall times (0.07/0.04 s). This oriented MOF thin film‐based high‐sensitive photodetector provides a new avenue to use inorganic, stable lead structures to assemble organic semiconductors into regular arrays, thus creating a huge potential for the fabrication of optoelectronic devices. [ABSTRACT FROM AUTHOR]

Tin halide perovskites are promising candidates for preparing efficient lead‐free perovskite solar cells due to their ideal band gap and high charge‐carrier mobility. However, the notorious rapid crystallization process results in the inferior power conversion efficiency (PCE) of tin perovskite solar cells (TPSCs). Here, a facile method is employed to manage this crystallization process by using cold precursor solution that raises the critical Gibbs free energy to slow down the nucleation rate, sparing both space and time for crystal growth. In this way, highly oriented FASnI3 films with micrometer‐scale grains are fabricated and an increase of 70 mV in the open‐circuit voltage is obtained for TPSCs. This method is compatible with other existed strategies such as additive engineering or the post‐treatment method. The best‐performing device that combines 0 °C precursor solution and post‐treatment method demonstrates a PCE of 12.11%. [ABSTRACT FROM AUTHOR]

Environmentally friendly InP-based quantum dots (QDs) are promising for light-emitting diodes (LEDs) and display applications. So far, the synthesis of highly emitting InP-based QDs via safe and economically viable amine-phosphine remains a challenge. Herein, we report the synthesis of amine-phosphine based InP/ZnSe/ZnS QDs by introducing an alloyed oxidation-free In-ZnSe transition layer (TL) at the core-shell interface. The TL not only has the essential function of preventing oxidation of the core and relieving interfacial strain but also results in oriented epitaxial growth of shell. The alloyed TL significantly mitigates the nonradiative recombination at core-shell interfacial trap states, thereby boosting the photoluminescence (PL) efficiency of the QDs up to 98%. Also, the Auger recombination is suppressed, extending the biexciton lifetime from 60 to 100 ps. The electroluminescence device based on the InP-based QDs shows a high external quantum efficiency over 10%, further demonstrating high quality QDs synthesized by this process.

Isotropic inverse opal structures have been extensively studied for the ability to manipulate cell behaviors such as attachment, migration, and spheroid formation. However, their use in regulate the behaviors of neural stem cells has not been fully explored, besides, the isotropic inverse opal structures usually lack the ability to induce the oriented cell growth which is fundamental in neural regeneration based on neural stem cell therapy. In this paper, the anisotropic inverse opal substrates were obtained by mechanically stretching the poly (vinylidene fluoride) (PVDF) inverse opal films. The anisotropic inverse opal substrates possessed good biocompatibility, optical properties and anisotropy, provided well guidance for the formation of neural spheroids, the alignment of neural stem cells, the differentiation of neural stem cells, the oriented growth of derived neurons and the dendritic complexity of the newborn neurons. Thus, we conclude that the anisotropic inverse opal substrates possess great potential in neural regeneration applications.

Control of the microstructure grain orientation, grain boundaries and thickness are crucial for MOF membranes. We report a novel synthesis strategy to prepare highly c‐oriented ZIF‐95 membranes through vapor‐assisted in‐plane epitaxial growth. In a mixed DMF/water vapor atmosphere, in‐plane epitaxial growth of a ZIF‐95 seeds layer was achieved to obtain an oriented and well‐intergrown ZIF‐95 membrane with a thickness of only 600 nm. Demonstrated by both experimental and simulation studies, the c‐oriented ZIF‐95 membrane displayed superior separation performance because a perfectly oriented structure resulted in a notable reduction of intercrystalline defects and transport pathways. For the separation of equimolar binary mixtures at 100 °C and 1 bar, the mixture separation factors of H2/CO2 and H2/CH4 were 32.2 and 53.7, respectively, with an H2 permeance of over 7.9×10−7 mol m−2 s−1 Pa−1, which was 4.6 times higher than that of a randomly oriented ZIF‐95 membrane. [ABSTRACT FROM AUTHOR]

Fluoride-mediated synthesis in the inorganic hydrothermal system has been proposed for preparing large crystals of layered Na/K-JDF-L1 with lamellar morphology. The protonated JDF-L1 crystals derived from their layered precursors are structurally modified by 1,6-hexanediamine intercalation under mild hydrothermal conditions. All the materials mentioned are characterized by XRD, FESEM, EDX/ICP-AES, and TGA–DSC. It is concluded that the combination of fluorides with low alkalinity (pH ca.10.0) and crystallization temperature (200 °C) facilitates the oriented growth of metastable layered phase Na/K-JDF-L1, yielding regular lamellar crystals with square-sheet structure in two-dimensions of ca. 15 × 15 μm. Data on Na/K-JDF-L1 structure are presented for identification of the most probable tetragonal space group, P4212, corresponding to the highest crystallographic symmetry. It is also revealed that amine intercalation of relevant H-JDF-L1 by the hydrothermal process leads to the formation of layered titanosilicate materials with an ordered redistribution of the dominant interlayer space (d001) shifting from 10.674 to 15.620 Å. [ABSTRACT FROM AUTHOR]

The passivated surface of nickel foam facilitates the growth of oriented nanosheet Ni-MOF instead of needle-like morphology. The nanosheet can maintain the structural stability during the followed pyrolysis and phosphatization treatment. The obtained Ni 2 P/C nanosheets on nickel foam are beneficial for the exposure of catalytic active sites and diffusion kinetics in HER. Tuning the structural features that furnish electrochemically active sites with improved kinetic diffusion can provide an alternative way to achieve high performance of electrocatalysis. Here, we report a nano-structure of Ni 2 P/C(NPC) nano-sheets supported on nickel foam (NF) that is prepared by sequenced nitrogen pyrolysis and gas phosphatization of Ni-MOF nanosheets. Initially, the passivated surface of nickel foam facilitates the oriented growth of Ni-MOF nanosheets, which is crucial for the maintenance of structure stability during the subsequent pyrolysis and phosphatization treatment. As a result, more catalytic active sites are exposed than the non-oriented NPC catalysts and diffusion kinetics is favorable. Consequently, the obtained composite can exhibit excellent hydrogen evolution catalytic activity in an alkaline electrolyte. For hydrogen evolution reaction, a current density of 10 mA cm−2 is provided at an overpotential of 97 mV and its onset overpotential is only 29 mV. Meanwhile, good morphology and catalytic activity can be maintained after 12 h of stability testing. This excellent performance is believed to be the result of NPC nanosheet structure on NF derived from the facet-oriented control of pristine Ni-MOF, enabling excellent reaction kinetics. [ABSTRACT FROM AUTHOR]

Monoclinic hafnia (m-HfO 2) films were prepared on polycrystalline AlN substrates via thermal and laser chemical vapor deposition (thermal CVD and laser CVD). Highly self-oriented growth of (020) and (002) m-HfO 2 films was demonstrated at a high deposition rate. Films prepared using thermal CVD exhibited a porous microstructure and no preferred orientation, whereas those prepared using laser CVD exhibited significant proportions of (020) and (002)-oriented m-HfO 2. The (020) and (002) orientations were observed to be as high as 90% and 98%, respectively. The (002)-oriented m-HfO 2 film exhibited a columnar structure with a feather-like texture in cross-section, and with a pyramidal faceted surface. Deposition rates of the (002)-oriented m-HfO 2 films reached 67 μm h−1, approximately 40 times greater than previously reported, thermal-CVD-grown m-HfO 2 films. Image 1 [ABSTRACT FROM AUTHOR]

This work is devoted to a simple method for synthesizing phosphors based on layered rare earth hydroxonitrates (LRH). Layered precursors of (Y 0.95 Eu 0.05) 2 (OH) 5 (NO 3)· x H 2 O with different morphologies were obtained via co-precipitation at a constant pH and hydrothermal methods. It was established that LRHs co-precipitated at pH 7 are highly ordered close-packed micron-sized plates with low porosity. With an increase in the pH of co-precipitation to 9.5, the phase composition is retained, but the isotropy and porosity of the particles increases sharply: the morphology changes from micron flat plates to curved nanosheets and nanoflakes. Co-precipitated LRHs crystallize more intensively into cubic (Y 0.95 Eu 0.05) 2 O 3 during heat treatment compared to precursors obtained under mild hydrothermal conditions (120 °C, 24 h). The structural characteristics of the material laid at the stage of synthesis directly determine its optical properties and the fundamental parameters of photoluminescence. The phosphors that co-precipitate at pH 7 demonstrate the highest yield of luminescence due to a more ordered structure, larger crystallite size, lower asymmetry factor and surface to volume ratio. The proposed co-precipitation method with a constant pH value of 7 allows one to obtain (Y 0.95 Eu 0.05) 2 O 3 phosphor with enhanced structural and optical properties compared to materials synthesized in hydrothermal conditions. The LRHs co-precipitated in this work are a promising precursor for the preparation of crystal-oriented and highly-efficient luminescent coatings and nanofilms. Image 1 • Co-precipitation at low pH causes oriented growth of layered rare-earth hydroxides. • Oriented growth form ordered plates with larger crystallite size and low surface. • The calcined phosphors inherit the morphology of the precursors. • Oxide phosphors from the plate-like particles show the highest luminescence yield. [ABSTRACT FROM AUTHOR]

The behavior and influence of a preformed Al alloying layer deposited on a silicon substrate on the morphology and orientational growth of arrays of ZnO:Al nanocrystallites have been studied. The stages of the decomposition of the Al doping layer into droplets of the quasi-liquid phase under the action of temperature treatment at the initial stage of the growth process by the vapor–liquid–crystal mechanism are shown. A scheme of the stages of growth of ZnO nanocrystallites by the vapor–liquid–crystal mechanism on a Si substrate with a preliminarily deposited doping metal layer is presented. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract The interface of an industrially-produced block of an alumina-zirconia-silica (AZS) refractory material with the mold is extracted and prepared for analysis. The first 24 mm of crystal growth including the cast skin are analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM) including energy-dispersive X-ray spectrometry (EDXS) and electron backscatter diffraction (EBSD). Apart from the bulk, two chemically different zones of crystallization occur near the interface to the mold. The growth model for this material begins with the primary crystallization of dendritic ZrO 2 followed by secondary crystallization procedures in the respective crystallization zones. The layer adjacent to the mold crystallizes to form alumina, secondary ZrO 2 and mullite. An 001-oriented layer of mullite with the c-axis oriented perpendicular to the mold material is formed in the second layer of crystallization while only alumina, zirconia and residual glass occur further in the bulk. [ABSTRACT FROM AUTHOR]

This study explained a procedure to synthesize 3D hexagram gold nanoparticles using a specific morphologically controlled gold precursor reduction. Acetaldehyde acted as the reducing agent along with polyvinyl pyrrolidone as the stabilizing agent with a limited reaction temperature range observed to be near to 25 °C. The resulting special gold nanoparticles were physically characterized and observed to possess an average planar size of 420 nm, an average central thickness of 200 nm, and an average edge thickness of 18 nm. Furthermore, a mechanism model was proposed to describe the oriented growth of gold nanoparticles employing published accounts of the mechanisms involved in the growth of gold hexagonal nanoplates. Moreover, the two major factors that controlled the morphology of synthesized gold nanoparticles were elaborated to provide reference for future fabrication methods of metal nanoparticles in both academia and industry. [ABSTRACT FROM AUTHOR]

Graphical abstract Magnetic nanostructures (MNS) of 2D ε-Fe 3 N nano-sheets and 1D Fe 3 O 4 /Fe 3 N heterogeneous nano-chains were synthesized through the electrochemical anodization without the assistance of any templates and surfactants for the first time. They can act as the directing agents of BiOCl growth. The intimate contact between MNS and 2D BiOCl was realized through the vapor-thermal method. Novel morphology of BiOCl and excellent photocatalytic properties were obtained. Highlights • 2D ε-Fe 3 N nanosheets and 1D Fe 3 O 4 /Fe 3 N nano-chains were synthesized. • BiOCl grows intimately on the surface of magnetic nanostructures. • Magnetic nanostructures act as the directing agents for the BiOCl growth. • Novel morphology of BiOCl and excellent photocatalytic properties were obtained. Abstract For the first time, magnetic nano-structures (MNS) of 2D ε-Fe 3 N nano-sheets and 1D Fe 3 O 4 /Fe 3 N heterogeneous nano-chains were synthesized through electrochemical anodization without the assistance of any templates or surfactants. 2D BiOCl nano-sheets were intimately grown on surfaces of these MNS via the vapor-thermal method and isopropanol and ethylene glycol acting as solvents. As a result, 2D-2D and 1D-2D magnetic photocatalysts were achieved. MNS function as directing agents of BiOCl growth and control the oriented growth of BiOCl; furthermore, they compress the BiOCl crystal lattice due to the strain at the interface between MNS and BiOCl. BiOCl grown on 2D nano-sheets exhibits a flower-like morphology that consists of square nanosheets, while exhibiting the morphology of epispastic sponge for BiOCl grown on 1D heterogeneous nano-chains. To the best of our knowledge, this has not been reported before. The synergistic effects of MNS and BiOCl enhance the absorbance in the visible-light spectrum. All magnetic photocatalysts exhibited excellent adsorption and degradation abilities to target pollutants such as rhodamine B, methylene blue, and phenol. Here, using MNS as directing agents opens up a new route to realize the oriented assembly and growth of BiOCl nanosheets; this strategy can be adjusted for the synthesis of other catalysts. [ABSTRACT FROM AUTHOR]