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K-doped porous g-C3N4 nanosheet (PNCN-K) photocatalysts were successfully prepared using urea, dicyandiamide and potassium bromide as reactants. The effects of K-doping on the microstructure and photocatalytic performance of PNCN were investigated. The results show that K dopants are introduced into the interlayer of g-C3N4. The PNCN-K photocatalyst with a suitable K-doping amount exhibits a lower bandgap and improved transfer and separation efficiencies of photogenerated electron–hole pairs. The photodegradation performance of RhB by the PNCN-K photocatalyst is greatly enhanced, which is 2.7 times higher than that of the undoped PNCN photocatalyst. Based on the radical capture experiments, it is confirmed that ·O2− is the main active species in the photodegradation of RhB by the PNCN-K photocatalyst. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) Ruddlesden–Popper perovskites with high exciton binding energy and great environmental stability have recently attracted great attention for their promising potential optoelectronic applications. The controllable growth of 2D perovskites with desired shapes would be critical for improving the performance of 2D perovskite-based optoelectronic devices. However, the investigation on this is still in its infancy. Here, we report on the controllable synthesis of 2D (C4H9NH3)2PbI4 microstructures with a butterfly shape, (C4H9NH3)2(CH3NH3)Pb2I7 and (C4H9NH3)2PbI4/(C4H9NH3)2(CH3NH3)Pb2I7 microstructures with a square shape by a solution-processing method. We have systematically investigated the influence of the substrate, mass ratio and crystallization temperature on the morphology evolution of the as-synthesized 2D perovskite microstructures. Atomic force microscopy (AFM) and optical microscopy (OM) images show that the size and thickness of the resultant products are positively correlated with their mass ratio and negatively correlated with their crystallization temperature. X-ray diffraction (XRD) patterns, fluorescence imaging, temperature-dependent photoluminescence (PL) and absorption studies confirm the crystalline structures and optical properties of the as-synthesized regularly shaped 2D perovskite microstructures. Our studies provide a simple method to controllably synthesize 2D perovskite microstructures without using very toxic solvents and thus offer a platform to investigate the optical and charge transport properties of 2D perovskite materials for the further design of new device architectures with enhanced performance. [ABSTRACT FROM AUTHOR]

As an unusual two-dimensional porous nanomaterial, a silica aerogel film was composited with a chiral nematic liquid crystal (N*-LC) to broaden the bandwidth. Here, a thin film of silica aerogel has been synthesized via ambient drying of the wet gel film that was obtained by the sol–gel process of tetraethoxysilane (TEOS). The porosity of the silica aerogel film depends on the hydrolysis and condensation of TEOS, and the modification of the microstructure of the wet gel film. The silica aerogel film/chiral nematic liquid crystal composite films were prepared by compositing the N*-LC with two kinds of silica aerogel films with different porosities. It is found that the reflection bandwidth (Δλ) of the composite film increased upon increasing the porosity of the silica aerogel film. Meanwhile, combining the anchoring effect of the polymer network, Δλ of the composite films was changed from 178 nm to 270 nm and the center wavelength was redshifted by approximately 120 nm. As a result, a presumed mechanism has been proposed to explain the effect of silica aerogel films on the N*-LC. [ABSTRACT FROM AUTHOR]

Polymer microparticles with complex microstructures, including cut spheres, bowl-like particles, hollow spheres with holes and porous hollow spheres, were prepared via phase separation in polymer microspheres. The incorporation of sulfonic acid groups is crucial, and the resulting microparticles are in sharp contrast to those prepared from regular polystyrene microspheres. [ABSTRACT FROM AUTHOR]

In this work, primary Mg2Si crystals shaped by {100} and {111} facets were successfully fabricated in Al–Mg–Si melts via the adsorption and poisoning of the Ca element. The modifier Ca plays an important role in determining the morphologies of primary Mg2Si, which can be transformed from dendrites (0 wt%) to crystals with a combination of eight {111} and four {100} facets (0.08 wt%), then to truncated cubes (0.1 wt%), and finally to cubes fully bounded by {100} facets (0.2 wt%) with increasing Ca content. The growth processes of cubic primary Mg2Si have been revealed. As the growth rates of {100} surfaces are diminished by adsorption of the Ca element, primary Mg2Si tends to form perfect cubes with exposed {100} facets. Moreover, by prudently adjusting the concentration of the Ca element, complex polyhedral crystals enclosed by {111} and {100} surfaces were designed and prepared. The results offer valuable insights into designing the modification effect of different modifying elements, which are critical to promoting the industrial application of light alloys with improved morphology and refined size of microstructures. [ABSTRACT FROM AUTHOR]

Correction for 'Antibody-coated microstructures for selective isolation of immune cells in blood' by Jiyu Li et al., Lab Chip, 2020, 20, 1072–1082, DOI: 10.1039/D0LC00078G. [ABSTRACT FROM AUTHOR]

A reduced graphene oxide/FeNi3/Fe3O4 composite was successfully synthesized by a one-pot solvothermal reduction method. The microstructure and morphology were confirmed through X-ray diffraction and scanning electron microscopy. The loss tangent parameters showed that the electromagnetic attenuation mechanism of RGO/FeNi3/Fe3O4 is mainly dependent on dielectric loss. The microwave absorption properties showed a maximum absorption of −46.6 dB at 12.5 GHz with a thickness of 1.9 mm. The absorption bandwidth with reflection loss below −20 dB is increased by 9.26 GHz (from 6.1 to 15.36 GHz) with a thickness in the range of 1.6–3.5 mm. The excellent microwave absorption properties of RGO/FeNi3/Fe3O4 make it a candidate for a microwave absorptive material. [ABSTRACT FROM AUTHOR]

A simple and facile hydrothermal method has been developed to enhance the fluorescence performance of YF3:xEu3+,y%Bi3+ (x = 0–0.2, y = 0–1.5) by optimizing the concentration of Eu3+ and Bi3+ and regulating the morphology/phase structure by controlling the amount of HNO3. The evolutionary mechanisms of the micro-topography and microstructure of the samples have been proposed, and the fluorescence and decay properties of the samples have been investigated. It was found that the fluorescence intensity of the sample has been greatly enhanced after addition of an opportune amount of Bi3+. The optimum concentrations of Eu3+ and Bi3+ for fluorescence are x = 0.125 and y = 0.5%, respectively. The significant enhancement in fluorescence performance could be obtained in the sample with the desired morphology at the optimum volume of HNO3 (VHNO3 = 11 mL). [ABSTRACT FROM AUTHOR]

This report introduces a platelike Ba0.5Sr0.5TiO3 (BST) mesocrystal synthesized by a two-step solvothermal soft chemical process. In the first step, a platelike layered titanate H1.07Ti1.73□0.27O4·xH2O (□: vacancy of Ti) (HTO) single crystal is treated in a Ba(OH)2 solution to obtain a platelike BaTiO3 (BT)/HTO/anatase nanocomposite. In the second step, the generated BT/HTO/anatase nanocomposite is treated in a Sr(OH)2 solution to obtain the platelike BST mesocrystal. The formation mechanism and nanostructure of the mesocrystal are investigated by XRD, TEM, SAED, and FESEM. The platelike BST mesocrystal is constructed from [110]-oriented BST nanocrystals and shows a set of single-crystal-like electron diffraction spots. The mesocrystal is formed via an in situ topochemical mesocrystal conversion mechanism. There is a definite relationship between the crystal-axis directions of the HTO precursor and the BST mesocrystal. The platelike BST mesocrystals with uniform microstructure and high crystallinity can be achieved by controlling the ethanol content in the reaction solvent. [ABSTRACT FROM AUTHOR]

Large scale β-sialon nanobelts/nanowires and ZrN–sialon composite powders were prepared via aluminothermic reduction nitridation under different conditions with flowing N2. The phase composition, morphology, and microstructure of the as-prepared products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM/HRTEM), Fourier-transform infrared spectroscopy (FT-IR) and energy dispersive X-ray spectroscopy (EDS). The experiment results show that the phase compositions and the ratio of nanostructures to powder can be tailored by the experimental conditions. The formation of β-sialon nanostructures was dominated by a vapor–solid (VS) mechanism. The photoluminescence spectrum of the β-sialon nanostructures exhibits a special emission peak located in the violet–blue spectral range, making possible potential applications in blue-light emitting diodes and display devices. This process also provided a feasible way to prepare reinforcing β-sialon nanostructures in situ within the ZrN–sialon composite powders. [ABSTRACT FROM AUTHOR]

In this paper, the synthesis, SERS performance and application in glucose sensing of hierarchical 3D Ag nanostructures (NSs) are reported. Large-scale Ag jujube-like architectures were produced via the galvanic reaction process in a mixed solution of trisodium citrate (TSC) and AgNO3 on Cu nanoparticles disproportioned from Cu2O membranes. X-ray diffraction, scanning electron microscopy, atomic force microscopy, high resolution transmission electron microscopy, and Raman spectroscopy have been utilized to characterize the as-prepared samples. It was found that the defects existed in the Ag crystals may play a significant role in the morphological formation of the building units of the self-assemblies. In addition, the optimum ratio of the Ag+ concentration to the TSC addition amount for preparing the desired Ag nanojujubes (NJs) was determined by studying the effects of the Ag+ concentration and the TSC addition on the morphology of the final products. The formation mechanism of the hierarchical 3D AgNJs was then discussed. Furthermore, in terms of sensitivity, reproducibility and stability, jujube-like hierarchical architectures constituted of Ag nanosheets with highly-roughened surfaces were proved to be promising for surface-enhanced Raman scattering (SERS) applications, which were further demonstrated in comparison with other AgNSs. It is also worth pointing out that jujube-like hierarchical Ag architectures performed well in glucose detection, which would have great potential in the biological and medical fields. [ABSTRACT FROM AUTHOR]

This paper presents a novel vapor–solid growth approach of stem-like 1D vanadium oxide nanostructures in a core-regenerated fashion on VO2@TiO2 core–shell rods under a very low temperature (400 °C). The composition and microstructure of the as-grown nanostructures were analyzed by HRTEM, EDS and XPS, confirming the vapor–solid mechanism. The confinement effect of the shell was analyzed by varying experimental parameters (coating thickness and heating rate), and the shell was found to play a critical role in generating and accumulating vapor with supersaturated concentration for the nanocrystal nucleation. Additionally, PVP was added as a surface modifier to favor the growth, probably by forming carbonaceous/nitrogen gaseous species as carrier media, as deduced by FTIR analysis. By exploring the impact of different heating rates, we found that the mass transfer process was facilitated only using a relatively high heating rate (＞1.33 °C s−1). However, such a growth was still limited only within the early stages (~15 min), because the confined vacuum interface will disappear with the progress of the crystallization of the nanoporous anatase shell. A unique 1D rods to 2D nano-flakes evolution can be achieved by increasing the heating rate from 1.3 °C s−1 to over 8 °C s−1. These findings provide a valuable understanding on the thermodynamics and kinetics during an unique VS based nanocrystal growing process, and also showed a new method to obtain hierarchical heterogeneous nanostructures. [ABSTRACT FROM AUTHOR]

La0.63R0.2Mg0.17Ni3.1Co0.3Al0.1 (R = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Y, Sc) alloys were prepared by induction melting followed by annealing treatment at 1173 K for 8 h. The alloys consisted mainly of a La2Ni7 phase and LaNi5 phases as explored by XRD and EPMA. Substitution of rare earth metals for La was favorable for the formation of a Ce2Ni7-type phase. Electrochemical experiments showed that all alloy electrodes exhibited good activation characteristics, that the discharge capacity improved with the substitution of Ce–Sc for La, and the La0.63Y0.2Mg0.17Ni3.1Co0.3Al0.1 alloy possessed the maximum discharge capacity (400.6 mA h g−1). At the same time, the cyclic stability of alloy electrodes was also improved by substitution of Ce–Sc at La sites, and the capacity retention rate at the 100th cycle was increased by 23.6% for the Gd-substituted alloy. The Yb-substituted alloy possessed excellent high rate dischargeability (HRD900 = 92.84%). All experiments implied that the alloy electrode with R = Gd possessed excellent overall electrochemical properties. [ABSTRACT FROM AUTHOR]

We demonstrate a novel synthetic route to fabricate a one-dimensional peapod-like Sb@C structure with disperse Sb submicron-particles encapsulated in carbon submicron-tubes. The synthetic route may well serve as a general methodology for fabricating carbon/metallic fine structures by thermally reducing their carbon-coated metal oxide composites. [ABSTRACT FROM AUTHOR]

By means of delicate and conventional methods based on photolithography and hot filament chemical vapor deposition (HFCVD) technology, a novel boron-doped diamond micro-network (BDDMN) film was fabricated, and this micro-structure showed excellent electrochemical sensing properties. [ABSTRACT FROM AUTHOR]

A new method of anisotropic etching an amorphous bulk material is proposed in this paper. Laminar flow is employed in this method to mask the flow of an etchant and is termed as “liquid etch mask”. Since this mask has the physical properties of a liquid, it brings several advantages that could not be achieved by any kind of other etch mask in the solid phase. As a consequence, the aspect ratio of the glass channel could be improved to ∼1 while in an inexpensive and convenient manner. [ABSTRACT FROM AUTHOR]